sendmail problem mail could not reach certain domains
Linux - ServerThis forum is for the discussion of Linux Software used in a server related context.
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Introduction to Linux - A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.
For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.
Click Here to receive this Complete Guide absolutely free.
We have a application hosted in our server and it uses send mail for sending and receiving mails. mails can able to reach certain ids but it cant reach some ids. this is the log entry.
Jan 6 00:52:18 p2234270 sendmail: p046hWi5011897: to=<email@example.com>, ctladdr=<firstname.lastname@example.org> (48/48), delay=2+00:08:46, xdelay=00:00:01, mailer=esmtp, pri=4530999, relay=smtp17.msoutlookonline.net. [126.96.36.199], dsn=4.1.8, stat=Deferred: 450 4.1.8 <email@example.com>:Sender address rejected: Domain not found
Jan 6 00:52:18 p2234270 sendmail: p03DiijH000913: to=<firstname.lastname@example.org>, ctladdr=<email@example.com> (48/48), delay=2+17:07:34, xdelay=00:00:00, mailer=esmtp, pri=6060704, relay=smtp17.msoutlookonline.net. [188.8.131.52], dsn=4.0.0, stat=Deferred: 421 4.7.0 exmf017-3.msoutlookonline.net Error: too many errors
what could be the problem?
Can any one suggest me how to proceed to resolve this issue.
Did you read what you posted? The problem is clearly marked:
Originally Posted by dinakumar12
<firstname.lastname@example.org>:Sender address rejected: Domain not found
The domain you're trying to send to isn't found. So either someone entered the wrong address/domain, or the domain has gone offline. Unless you own that domain, there's nothing you can do, other than don't send emails to them. The domain www.msoutlookonline.net responds, but not what you've got in your logs...did you try to even hit that domain with a web browser, or do a lookup on it?
You are fighting exactly the same thing I am facing. The mail server you connect to, in this case smtp17.msoutlookonline.net tries to lookup the senders domain, p2234270.pubip.serverbeach.com and it doesn't find it. So, either you have to make an A record in you DNS server for that server or find a way to masquerade the senders address. I've been trying to find a way to masquerade the ctladdr but with no luck so far. But I'll keep on looking.
In order to help combat SPAM, certain behavior and criteria or generally expected out of mail servers. Legitimate mail servers need to operate from a domain with a static IP that is also not classified as being part of a residential network. These servers must have valid DNS entries and should have reverse lookups that map back to the originating domain. In addition there are more recent tools such as SPF records and domain keys, which are also used to validate that the originating host is in fact a legitimately declared mail server.
By similar token, organizations can declare which hosts are the public facing mail handlers for their domain. In this particular case, msoutlookonline.net, declares that smtp.msoutlookonline.net. is their designated mail handler, not smtp17, which is undoubtedly an internal handler for their system.
Attempting to send mail to invalid domains, failure to use proper DNS techniques to identify your originating domains, etc will get you blacklisted and shut down faster than you can blink, and rightfully so. This is also why most major recipient domains will, by default, treat you as a spammer and automatically black list your servers until you prove to them otherwise. Trying to masquerade and obfuscate the IP addresses in question makes you look like you are up to no good. Mail handling requires two may communication between hosts. This makes IP address spoofing nearly impossible and this is by design.
Thank you for a good answer dinakumar12. What I was trying to do was get the sender to be something else then localhost@localhost.
I'm still working on this but not crazy though. I understand what you are saying, it makes sense and is of course necessary.
@OdinnBurkni, please note that this thread is over a year old. If you wish to resume this discussion please create a new thread and post a link to this one for reference instead of continuing an old post as they get confusing and discombobulated.