Solved

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

Posted on 2008-10-08
4
1,386 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
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 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

Transaction Monitoring Vs. Real User Monitoring

Synthetic Transaction Monitoring Vs. Real User Monitoring: When To Use Each Approach? In this article, we will discuss two major monitoring approaches: Synthetic Transaction and Real User Monitoring.

Question has a verified solution.

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

Workplace bullying has increased with the use of email and social media. Retain evidence of this with email archiving to protect your employees.
Easy CSR creation in Exchange 2007,2010 and 2013
In this video we show how to create a User Mailbox 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 >> Mailb…
In this video we show how to create a Shared Mailbox 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 >> Sha…

695 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