Solved

Debian Etch - Postfix - mailname different from hostname - is this a problem?

Posted on 2008-10-08
4
1,363 Views
Last Modified: 2013-12-09
We are installing a Debian Etch server with Postfix as the mail server. During the test all seams fine except sending emails to some servers. Sending to certain addresses it looks like the email has been sent but never arrives to the destination mailbox.

In the mail.log it sais : "...lnxsrv postfix/smtp[6065]: .......to=<tom@targetdomain.com.au>, relay=targetdomain.com.au[...]:25, delay=31072, delays...,dns=4.4.2, status =deferred (lost connection with targetdomain.com.au[202....] while receiving the initial server greeting)

In the mx record the server is office.clientdomain.com.au while the actual hostname of the server is lnxsrv, fqdn is lnxsrv.clientdomain.com.au. I have tried it with mailname set to lnxsrv and also with setting it to office, neither seam to resolve the issue.
The client can send email to servers not hooked up with postini service, but not to the one using postini spam/AV filtering service.

any clues?

TIA,

Tom
0
Comment
Question by:tom_szabo
  • 2
4 Comments
 
LVL 19

Accepted Solution

by:
bevhost earned 500 total points
ID: 22683345
Check that the Servers Name (HELO greeting it sends) is a name that can be looked up in the DNS.
Check that it resolves to your server.

Also check that the Reverse DNS for your server also has a matching A record pointing back to the Server.

See Section 2.1 of...
http://www.faqs.org/rfcs/rfc1912.html
0
 
LVL 19

Expert Comment

by:bevhost
ID: 22683355
I once had a client who was sending emails from a .com.au email address from a computer that had a .co.nz server name and the IP address whois was owned by a japanese ISP.

He wondered why I was blocking his emails.

I used a package called policyd-weight to do this checking.
I imagine that postini does similar things.
0
 
LVL 13

Expert Comment

by:Xyptilon2
ID: 22855853
Initiate a manual conversation with the receiving mailserver (MX record) using a telnet based program. Or if you can, enable conversation logging with a program like "recordio" to debug the issue.

Reverse DNS lookups are sometimes done as an anti-spam measure, if it doesn't match a match is flagged, or sometimes even blocked. To make this match with the IP in the header of the email, ask the manager of your IP range (not the DNS provider, although sometimes it's the same person) to setup a PTR record for your IP address mapping back to your FQDN.
0

Featured Post

Free book by J.Peter Bruzzese, Microsoft MVP

Are you using Office 365? Trying to set up email signatures but you’re struggling with transport rules and connectors? Let renowned Microsoft MVP J.Peter Bruzzese show you how in this exclusive e-book on Office 365 email signatures. Better yet, it’s free!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

New-MailboxSearch Powershell Command and step by step approach to Search and Extract Emails form Exchange 2013 Journaling server.
Resolve DNS query failed errors for Exchange
In this video we show how to create a Contact in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >> Contact ta…
In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…

895 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now