A configuration was introduced ( from the holy powers ) which happens to cause our server to backskatter and I am trying to fix the problem on our end ASAP. com address. Player 23 - DM - Player 87 - DM. yesterday, just the iPad started not sending emails saying ‘the recipient was rejected by the server because it does not allow relaying’ I have performed all of the above and it still does not work have you any ideas please? thank you. I have multiple fixes I will be showing. com" was rejected by the server Then you most probably did not set SMTP authentication when the email account was configured on that specific device. com as the outgoing server but none of this has worked for me. To fix the “Inbound from Office 365” receive connector, you need to both populate the list of allowed IP-addresses and enable the receive connector for relaying. In most organizations there are several devices or applications that need to use an SMTP service to send email messages. 251 – The recipient is not local to the server, but the server will accept and forward the message. Provide details and share your research! But avoid …. Server Hostname Note: Apple may collect and use your domain address (i. 30 can not only relay, but relay to external domains. 0 ports 24/7. Back in the early days of email, just about all mail servers let you relay mail though them. Followers 3. You need to check the account settings for your mail program and make sure it is set for the right mail server. I changed the settings on both my iphone and ipad by creating app passwords. This is how to fix problems in Yahoo Mail: I get a message that yahoo server does not allow relaying. Update: Yesterday, Apple released iOS 11. However, some ISPs will not allow a third party program like RDP to send e-mail using their SMTP server because of concerns about spam and viruses. Had to change password and use STARTTLS When the email was received the from address had been changed from [email protected] For more details, see the Sharing section. The 'Allow all computers which successfully authenticate to relay', regardless of the list above option, is also enabled by default, which allows users and computers that can authenticate with the server to relay through the server. Go to Settings-> the next menu depends on your version of iOS. Fix problems with New Mail: Unable to send email , rejected by server, does not allow relaying? Add your answer. Microsoft Exchange server: server is setup to block SMTP relaying. What type of email account? What antivirus do you use? Does it scan outgoing email? If you can send to everyone except this one person, the problem may be with their server, not yours, but if you use a virus scanner on outgoing email, you may need to add that ip address to the scanner's allow list. This happens regardless of the recipent. severity 648401 grave retitle 648401 DHCP relay agent does not listen properly for return packets thanks On Fri, Nov 11, 2011 at 04:53:22PM +1100, Geoff Crompton wrote: > The dhcrelay man page doesn't mention that if you use any -i option to > specify interfaces, you need to add an -i option for the interface used to > contact the DHCP server. Figure 1: With this configuration, your Exchange Server's SMTP service never has to interact with an Internet SMTP server. Wired clients on my network work perfectly fine. Wrong Incoming Server(pop3) and Port for your Email Setting; Issue with Sending. When you see the “Server does not allow relaying” error, it means that the email can’t be sent and the following message will start showing up on their iPhone 7 and iPhone 7 Plus: “A copy has been placed in your outbox. 1 Indicates that the server has accepted the command, but does not yet take action. I hope they fix this quickly. If it does, then the machine is allowed access. It’s sad that if I knew what I did today back then about PAS I wonder if my daughters would be still here or not? But I do know this one thing for sure, the courts don’t care. I would appreciate any help you can give. How to configure an Office 365 SMTP Relay Connector. Anyway, glad you are up and running. This happens regardless of the recipent. This weakness allows stealing the information protected, under normal conditions, by the SSL/TLS encryption used to secure the Internet. Mail Relay is when you connect to a mail server on another domain and try to send mail. The last line saying :allow is redudent. If you do see traffic headed to the mail server its possible that the security on the mail server will not allow you to relay from that. In fact, Windows Server 2016 still uses IIS 6 tools to host and manage the SMTP service. Your organization has to send non-delivery reports (NDRs) from the on-premises environment to a recipient on the Internet, and it has to relay the messages through Office 365. If you need to allow a server to relay, you'll need to create a Receive Connector and allow relaying for that server's IP address. wrong connection values for the SMTP server 2. " If so, you are not alone. This Connector will allow Anonymous Connections (not Relaying) while your Default Receive Connector will be utilized for internal routing. So far I have found that the issue is that Telstra will not let Optus send emails through their network. Each entry describes the problem and links to the fix it page at the Microsoft Support website. Quick Malware Scan and Removal Guide for PC's. I have tried resetting the smtp many times, and although have all the correct information, this never works. You will need to access yuor home hubs settings and aplly port forward rule for the smtp server. I have this problem since 06-08-2018 Telkom cannot help to restore. When you start to send the server gets part of your information but does not complete the transaction. Fixing email delivery issues is one of the top three things we do for our server management customers. People are facing this problem after upgrading to iOS8. This post highlights the steps on how to setup and manage email accounts on your new iPhone 8 using Mail app in iOS 11. The virtual server's default configuration allows only authenticated computers to relay mail. Select the Primary server at the top. [email protected] In the meantime, you can use your mail access domain for your outgoing server instead. Bulk email software for Mac OS and MS Windows that allows you to send out customized press releases, newsletters, prices lists and any kind of text or HTML documents to your customers or contacts. Yes, after applying the temporary fix, the issue reoccurs for me still as well. My SMTP logs are swamped with "Refused Relay" entries (1000's of them). If you do see traffic headed to the mail server its possible that the security on the mail server will not allow you to relay from that. I also toggled the SMTP settings a few times but I am still getting the same message that "the recipient was rejected by the server because it does not allow relaying". The recipient (my email address even though addressed not to me but to others) was rejected by the server because it does not allow relaying. I comes up with a message saying that server does not allow relaying. View 1 Replies View Related IPhone :: Email Recipient Is Rejected As Server Does Not Allow. Check the "My Server Requires Authentication" check box and the adjacent "settings" button. To the mail server, it looks like you are trying to disguise your identity. xx was let thourgh, because tachnically, the NAT'd address. org then please do not send us e-mail, the reply of the sendmail maintainer will not reach you. IIS SMTP Server settings. Best Free Antivirus Programs for Home use. Discussion in 'Plesk for Windows - 8. I used to be able to send emails from this handset and haven't had this phone connected to iTunes for a few weeks now. However, some SMTP servers are configured to explicitly block ping requests. "A copy has been placed in your Outbox. This Connector will allow Anonymous Connections (not Relaying) while your Default Receive Connector will be utilized for internal routing. Re: SMTP Relaying denied I configured my MX record to direct mails to the smtp subdomain (and the config does specify smtp subdomain). mailbox is full and the server will not accept any more messages until the user make more space available. Click the email account (which you trying to send mail). Your ISP's mail servers do not allow. Had to change password and use STARTTLS When the email was received the from address had been changed from [email protected] 2) Microsoft Exchange server: server is setup to block SMTP relaying. Microsoft Exchange server: server is setup to block SMTP relaying. Most - but not all - of the email I attempt to send from my iPhone X fails, with the error: "Cannot Send Mail. But you could always add the relaying mail server to the sender domains SPF record. Outlook)?. 1 Indicates that the server has accepted the command, but does not yet take action. Smtp related errors may have different numbers and slightly different wording, eg, "Relay access denied for", but are all related to the same problem. And how to disable the limit completely then? Totally common to use zero values to disable in such cases. xx so that mail would be forwarded, all the mail coming in from my nat's address 199. If you are trying to send a large attachment with your email and are not able to, please contact your email account provider for further assistance and information. A Telnet test involves establishing a Telnet session from a computer that is not located on the local network to the external (public) IP address of the Exchange server. the attacker would be able to delete files on the server, but not install or execute code. I have multiple fixes I will be showing. The recipient was rejected by the server because it does not allow relaying. In answer to your first question, there is nothing that you need to do on an Exchange Server 2003 to stop spammers from relaying. Hey guys, I'm a total n00b, so I'm sorry if this is a stupid question. For more information and answers to commonly asked questions, see the SmarterTools Support Policy. Usually something like relay access denied (by remote server, not my own server), or SPF record related such as the one I just got today: 550 5. log file if it mentions connecting to the ldap server. However, you will want to change this to use Google’s free SMTP server. ‘rejected by the server because it does not allow relaying’ message. Vraag dus bij uw mailprovider naar mogelijkheden om mail via een ander netwerk te versturen, waarschijnlijk krijgt U dan het advies om webmail te gebruiken of alleen. 1 or later) sendmail does not allow for the receiving of mail except from yourself (localhost). However, the Cisco IOS DNS server does not perform zone transfers. So far I have found that the issue is that Telstra will not let Optus send emails through their network. Thoughts on arch as a server os I may soon~ish find myself in a position where I have to setup a small-scale infrastructure for a friend and the one question that is keeping me awake at night is what distro to use. com it sends. Neither can a server hosted by InMotion that we still have an account on. Verify your details and click on More Settings. Possible causes: Email client is not configured for SMTP authentication and the server is. Authenticated SMTP relaying in Exchange 2013 Comments (7) | Share Recently I designed and implemented a large Office 365 environment, part of it was a Hybrid Exchange 2013 server that should also serve as a central SMTP relay server to 365 and the rest of the world. It turns out, that some firewalls are corrupting data, if it is sent in small chunks. Being unable to send an email can ruin your workday, wreck productivity, or even worse cause you to lose out on an valuable opportunity. Steps to resolve error Exchange SMTP Error 550 5. IMAP, or Internet Message Access Protocol, is a newer protocol that is not used as widely as POP3. Microsoft Exchange is by default configured with extensive privileges with respect to the Domain object in Active. So our examination of the numbers leads us to suggest adding 2 disks to each controller and relaying out the data. However, this is enough to test your domain and SMTP configuration. wrong connection values for the SMTP server 2. You will need to contact your Internet Service provider and ask for the outgoing mail server settings. " How can I fix this so I can send mail from IPAD. KB ID 0000542 Dtd 06/12/11. But if you don't want to (or can't) mess with the startup file, or more important, if you are on a server where each app may need to do its own setting, you're not out of luck. Bug Fix: not all local IP address were detected on some Unix platforms. Ipad 2 Outgoing Mail Server Problems If you can't get or send mail with a Gmail account on your iPhone, iPad, or iPod touch, follow these steps. So keep it safe, with smtp authentication enabled or with allowed relay but only from internal/external trusted hosts. com", your aol username and password. Here is a post by Malwarebytes. If you're affected, you need to complete the following steps to update your version of OpenSSL and secure your server. If you are using the blacklist from spamlist. 4) To check if the ldap authentication is working, just try to do sudo to a user and check in the /var/log/auth. Configuring relaying. i already use smtp port 25, 465 and 587 but still cannot send out the msg. If you enabled 2-Step verification for your Google account, you'll be able to sign. com / pop-server & mail-hub should be working, as you would be getting an IP that is friendly to the BP mail serversand I can only assume iPrimus would work the same way. The old adage of, ‘If it isn’t broken, do not fix it’ comes to mind. Consider setting up a test site to play with the new version. The 'Allow all computers which successfully authenticate to relay', regardless of the list above option, is also enabled by default, which allows users and computers that can authenticate with the server to relay through the server. If the line contains permit before reject, this is a finding. Fixing email delivery issues is one of the top three things we do for our server management customers. I keep getting a message that the a copy has been placed in your Outbox. After successfully installing Exchange Server 2013, you can now configure the server to send and receive outside Email. Receive message that email was rejected by server because it does not allow relaying. Whilst the launch of iOS 11 yesterday has. All Microsoft Fix It solutions can be accessed at the Microsoft Fix It Solution Center. I comes up with a message saying that server does not allow relaying. Rejected by server becuase does not allow relaying iphone 4 centurytel email setup. Look on the Outgoing Server tab. The SMTP server does not allow relaying unless you are sending email from a trusted IP or use proper authentication. 3 Client does not have permission to Send As this sender. To synchronize your Gmail account with an outside email client, such as Outlook, give the server instructions for how to send your Gmail emails in the form of Simple Mail Transfer Protocol (SMTP) server settings. Postfix as a client to Exchange, this is not working. I hope I included all > necessary configuration files in my last mail. com-Konto> Konto> SMTP von der Kontoinformationsseite> SMTP von der SMPT-Seite> Stellen Sie sicher, dass der Server ist AUF. Then he wanted the the. Ways to fix server does not allow relaying error on iPhone 8. Asking for help, clarification, or responding to other answers. Verify your details and click on More Settings. In my experience usually OJS is not problem. About iPhone, iMessage, iOS 12, iPad, Mac, phone solutin bug fix, how to iPhone iphone 5 Can not send emails :email server does not allow relaying Skip to main content. I followed all the steps above except for when I got to number four. well if you can't allow relaying unauthenticated. The SMTP server does not allow relaying unless you are sending email from a trusted IP or use proper authentication. Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN) draft-ietf-tram-turnbis-15. This article explains how to fix the Cannot Send Mail. Bug Fix: not all local IP address were detected on some Unix platforms. Since most firewalls do not allow FTP data channels to be set up by clients on ports below 1024, the ports an attacker can target are limited to the 1024-65535 range. The issue started for me the same time as the original poster. Scenarios in which Office 365 does not support relaying email messages by default. My phone works ok for email - Answered by a verified Email technician. Ways to fix server does not allow relaying error on iPhone 8. I followed all the steps above except for when I got to number four. Value that is set in IMAP "Server software" configuration option can fix search issues in EIMS or hmailServer, provide workarounds for some folder subscription errors in mercury32 IMAP server, but it does not affect system folder names, folder prefix, delimiter and other specific configuration options. It's not a POP server. I comes up with a message saying that server does not allow relaying. IPhone :: Email Sent From 4S Rejected By Server - Relaying Not Allowed? Apr 17, 2012. I am trying to send email to a yahoo address and get "550 relaying mail to Yahoo. 1 Relaying not allowed. I have problem with my outlook 2007, this case i can connect to zimbra pop3 by outlook but cannot send out. Therefore, DO NOT remove this # retry rule unless you really don't want any. Knowledgebase. 501 Not Implemented The server does not have the ability to fulfill the request, such as because it does not recognize the request method. Value that is set in IMAP "Server software" configuration option can fix search issues in EIMS or hmailServer, provide workarounds for some folder subscription errors in mercury32 IMAP server, but it does not affect system folder names, folder prefix, delimiter and other specific configuration options. By default, Microsoft SMTP Service blocks computers from relaying e-mail that you do not want through the SMTP virtual server. I also toggled the SMTP settings a few times but I am still getting the same message that "the recipient was rejected by the server because it does not allow relaying". Server error: '550 5. This is common with multi-function devices such as network attached printer/scanners, or applications such as backup software that send email reports. This can be dangerous if not set properly as if you will just enable Allow relay on your server it will allow everyone to relay emails thru your server which means all the spammers will use it. I have the same problem and restarting the SMTP service from both ME and the 'Services' admin area does not rectify the problem. Accumalux but problem is that open relay is fine configuring on my both SMTP server since long time ago and Xampp with my OSticket dev inside, is able to send email without trouble. The basic principle is that the server is relaying those packets for you, and stripping the originating address. Additionally, two of them were marked to play Sounds and nothing else (no banners, alerts, badges, etc). People are facing this problem after upgrading to iOS8. I can pull down email via mobile internet fine. In fact, some people say iPhone can’t email right. If your ISP does not allow RDP to send e-mails, use the Microsoft SMTP server on either the IRM server or RDP data server. net to read those emails, but you could use smtp. I never got the message "does not allow secure connections" until I started letting Plex's servers do their thing, and I only get it when connecting from outside my home network. The recipient was rejected by the server because it does not allow relaying" I really don't know what this means or how I can rectify it. 3 Refers to the server has understood the request, but requires further information to complete it. The recipient has a non-SMTP address that can’t be matched to a destination. To secure this set up, for incoming mail, allow the IIS SMTP server to. I get a message stating that the email could not be sent because the recipient's "server does not allow relaying". Also added a few other miscellaneous SMTP status checks to insure a message gets correctly forwarded to the selected SMTP server. Relaying is not allowed by Charter. Note: If your use case is to receive notifications from your server at a single address, emails being marked as spam is not a significant issue, since you can whitelist them. Configuring relaying. Some less likely possibilities are : You're blackballed (your domain is listed as a spammer by some anti-spam listing service). 503 This mail server requires authentication. without providing a username and password to send email. In my experience usually OJS is not problem. Relaying is the process of accepting an email and delivering it to non-local email address(es). It turns out, that some firewalls are corrupting data, if it is sent in small chunks. When you open this page, click on all of the plus signs (+) to see the details for the procedure. The recipient was rejected by the server because it does not allow relaying. qmail files though. check to see if your hosting company provides you a secure SMTP service, if not, maybe your ISP has a secure smtp setting that will provide what you need. From the security perspective that is really good, nobody will be able to use our Exchange Server 2016 to relay messages to other domains that we haven’t configured in our Exchange Organization, however for an internal service/application that needs to relay messages to external users, that is not good and we need to allow them to do that. This is called relaying and most ISPs won't allow it. Hi, I keep getting the message it can't send my email the recipient was rejected by the server because it does not allow relaying. We relay to an offsite mail server for a few of our users ( contracted mail hosting ) 2. 95% of notifications work, but some users consistently cannot send out notifications. "mail('[email protected] Here is a post by Malwarebytes. The connection to the server 'smtp. Your ISP's mail servers do not allow. This means that an unauthenticated, remote user could possibly use the mail server to send messages to the world, thus wasting network bandwidth and computer resources. This is common with multi-function devices such as network attached printer/scanners, or applications such as backup software that send email reports. When you see the "Server does not allow relaying" error, it means that the email can't be sent and the following message will start showing up on their iPhone and iPad: "A copy has been placed in your outbox. I can`t send emails from my samsung 335 chat. Thus, even if the ping packet timeouts, you should still try to telnet the SMTP server unless absolutely sure that ping command should not be blocked. Sending the message content to the server failed. Please remember to click "Mark as Answer" on the post that helps you, and to click "Unmark as Answer" if a marked post does not actually answer your question. To fix this loophole, it is wise to deny TCP connection to port 25 from your dialup modems to all outside hosts. You can setup a receive connector on your local Exchange configured to allow relaying or just use option 3 to send directly to We are running a Hybrid Exchange setup with all mailboxes in the cloud. org then please do not send us e-mail, the reply of the sendmail maintainer will not reach you. How to Fix Server Does Not Allow Relaying Error on iPhone 8 1. For example: acl myclients src 172. If this is set to something other than smtp. The recipient was rejected by the server because it does not allow relaying. net" is the account I am trying to send the email FROM on my iPhone. How to fix '550 Relay not permitted' in Outlook Express on OS X:. This message appears because your iPhone or iPad does not have the correct sending SMTP settings. If you are behind multiple routers and if you can, either connect your PC directly to the modem OR connect it to only one router that has a direct line to your modem. All of my messages are sitting in my outbox and I'm getting a message "Cannot Send Mail: the recipient was rejected by the server because it does not allow relaying. Consider setting up a test site to play with the new version. Solution for 6, 7, or 8: Changing it programatically. Click on Airplane icon to enable Flight mode. Recently, many iPad users complain that their iPad cannot send emails at all!. Your organization has to send non-delivery reports (NDRs) from the on-premises environment to a recipient on the Internet, and it has to relay the messages through Office 365. So far I have found that the issue is that Telstra will not let Optus send emails through their network. How do I enable SMTP Authentication in an MS Outlook Client? Ensure the Outgoing server How is SMTP authentication used to allow or deny relaying based on. Most - but not all - of the email I attempt to send from my iPhone X fails, with the error: "Cannot Send Mail. I even went into passwords and settings and into my email account and it will not let me click on anything in the outgoing mail section. Server Hostname Note: Apple may collect and use your domain address (i. Where would server does not allow relaying fix get a speaker like this, CyberGuys or Frys. I have tried resetting the smtp many times, and although have all the correct information, this never works. I comes up with a message saying that server does not allow relaying. We have several devices and applications that do not support Office 365 authentication requirements so we. deny to see if the client matches a listing in there. com Looks like I will have to stick to the substitute domain for smtp until I can get the problem fixed. Hey guys, I'm a total n00b, so I'm sorry if this is a stupid question. Get help setting up and using your Hover email. The customer's SMTP server only allows relaying to internal addresses, so I asked the user to speak with their IT team to determine the best approach for relaying messages to an external address. " You should be relaying from your own machine or forwarding to your ISP's smtp server. A copy has been placed in your Outbox. If you just installed or upgraded to red Hat 7. -- Chris LAN. This issue is caused by the option to relay messages not being enabled on the SMTP server. Some servers allow you to send email in …. I do not have any problems receiving. Outlook,hotmail. 2) Microsoft Exchange server: server is setup to block SMTP relaying. Don’t worry, this is easy to fix! Quick Tip: Mail was rejected by the server because it does not allow relaying By Jeff Fraser Time to Read: 1 min. This happens regardless of the recipent. Microsoft Exchange server: server is setup to block SMTP relaying. Note: If mail relaying is not configured properly, then your mail server could be commandeered to relay spam. If your ISP does not allow RDP to send e-mails, use the Microsoft SMTP server on either the IRM server or RDP data server. couldn't Server does not allow relaying email error, fix. This is not # recommended for today's Internet. 'rejected by the server because it does not allow relaying' message. # If you are not doing any relaying, you should leave the list empty. Ipad 2 Outgoing Mail Server Problems If you can't get or send mail with a Gmail account on your iPhone, iPad, or iPod touch, follow these steps. The weird thing is that I have 2 server in a DAG, my primary server does not send email relay, however the secondary server sends. Ok, so for the last 3 days or so I've been experiencing a problem with my SBS 2003 server. It also happens to a friend of mine who still has the iPhone 3G but has updated software. Mail was rejected by the server because it does not allow relaying If you just set-up your new Local Propeller email account on your iPhone things are normally. The basics of using a proxy server for privacy and security. Flash Player 9 does not allow keyboard input when displaying content in full-screen mode. However, when the server queries the A record for the domain named in the PTR record, it does not match the original IP address. Anyone had any problems with this before? Any time I try to send an e-mail, I get a message that says "A copy has been placed in your Outbox. Scenarios in which Office 365 does not support relaying email messages by default. com) is not processed by the Simple Mail Transfer Protocol (SMTP) or outgoing server that the sender is requesting to deliver the message. Ps I am not a computer minded person so plain 'talk' would be appreciated Thank you. So our examination of the numbers leads us to suggest adding 2 disks to each controller and relaying out the data. Exchange Server 2003 is a closed relay. You also need to uncomment "allow_domain_literals" below. com email addresses. Are you getting this message when you send to a specific email client (for example Earthlink. Checking your outgoing mail server (Is Port 25 blocked?) What can I do if port 25 is blocked? A: You may also choose to use the alternate Port 587. com address. 1)", means that you are trying to send email using the wrong smtp server. How to fix Windows 10 Update Problems. How Can We get Email Working With Jim2? It's best to set up an open relay server that does not need authentication. Re: Cannot Send Emails - Using My Own Domain Email addressc+ Outlook 2007 BT Home Hubs as default will have smtp server port blocked ! they say they arent but they are. I've set up a new Receive Connector under hub transport and now my SNAP server can send me warnings but not my HP Systems Insight Management software. It's probably not a firewall issue on your end (telnet is not usually blocked by the default configuration of a firewall), although it is possible. " You should be relaying from your own machine or forwarding to your ISP's smtp server. If the machine does not match an entry in hosts. Instead of your. "mail('[email protected] Okay, I think I have determined that the Astaro box is not relaying (still not 100% sure however, I still need convincing). Please be more specific what was working and what not. 0 FREE; How to Block Porn Sites on all Web browsers & Network Devices. You will need to contact your Internet Service provider and ask for the outgoing mail server settings. I comes up with a message saying that server does not allow relaying. Switching the FMS to use a smaller maximum segment size should fix the problem. I get a message stating that the email could not be sent because the recipient's "server does not allow relaying". Figure 1: With this configuration, your Exchange Server's SMTP service never has to interact with an Internet SMTP server. The recipient "[email protected]" was rejected by the server because it does not allow relaying. We will not reply to those annoying mails. Select the Primary server at the top. By relaying your emails through another mail server that is hosted on a static IP address in a data centre (e. Like it so far but have a problem that can very well be a deal breaker. You cannot relay through any SMTP server (unless that SMTP server is an open-relayand that's a bad thing. error: rejected by the server because it does not allow relaying. Server will not allow relaying keyword after analyzing the system lists the list of keywords related and the list of websites with related content, in addition you can see which keywords most interested customers on the this website. By default, Exchange 2010 does not allow anonymous relaying. By default, the SMTP virtual server allows relaying only from authenticated users. Hey murraywood I checked on this message and this happens when the address you're sending to doesn't support the relay service that delivers the message. When it receives a DNS query, an authoritative name server handles the query as follows:. Hey all, I'm setting up the relaying option on my Exchange server so my other servers can send me a text message when they have a serious problem. The recipient "[email protected]" was rejected by the server because it does not allow relaying. The DNS server that the network hosts use to resolve hostnames if the primary and secondary servers do not respond.