Tag Archives: exim

Retry timeout exceeded – Exim greylist problem

This article relates to Exim 4, running in a WHM/cPanel environment under Centos, but may affect other configs too.

You may find instances where a local user tries to send mail to a host that operates greylisting. The messages never gets to the recipient. You see things like this in the exim_mainlog

2011-11-10 15:14:05 1ROWKK-0003I1-Ia <= localuser@localdomain.co.uk H=something.com (FredBlogs) [2.2.2.2] P=esmtp S=7852 id=!&!AAAAAAAAAAAYAAAAAAAAAEDCVk4NrhRJjsshyvaOnAfCgAAAEAAAAOV7jpjiT51Jm/WbyNPkywIBAAAAAA==@domain.co.uk T="FW: test" for remoteuser@remotedomain.co.uk
2011-11-10 15:14:06 1ROWKK-0003I1-Ia == remoteuser@remotedomain.co.uk <remoteuser@remotedomain.co.uk> R=lookuphost T=remote_smtp defer (-44): SMTP error from remote mail server after RCPT TO:<remoteuser@remotedomain.co.uk>: host mail.host100.co.uk [5.5.5.5]: 451 Greylisted, please try again in 223 seconds
2011-11-10 15:14:06 1ROWKK-0003I1-Ia ** remoteuser@remotedomain.co.uk: retry timeout exceeded
2011-11-10 15:14:06 1ROWKK-0003I1-Ia Completed
Read More…

Exim Queue Management Tutorial

So, you have got yourself a shiney new dedicated or VPS server with cPanel or DirectAdmin or some such installed. It probably won’t be long before you have to start checking the exim mail logs and the exim mail queue to trace problems being encountered by customers.

I have put this article here more as an aide-memoir than anything. If anyone finds it useful, I’d love to hear from you!

Respect the exim queue

One of worst things you could ever do as an admin, when finding a mail queue with hundreds or thousands of frozen or delayed messages in it, is to simply clear the queue. DONT DO THIS! You might just as well not run a mail server at all. The messages you remove in this way will just vanish without a trace – your customers and the people they communicate with won’t have a clue what happened, and your service will soon be viewed as unreliable.

Sadly, many inexperienced admins use the graphical UI to do just that – because it’s easy. However, with just a few simple commands, it can become possible to inspect and manage the queue with much greater elegance.

So, read on to find out how Exim queue management can be done from the command line. Read More…

How to Configure Exim to receive email for domain only from specific IP addresses

This article describes one way to limit incoming SMTP connections for specific domains to a list of specific safe relay IP addresses. Let’s suppose that you have a domain, mydomain.com – and you want to filter all email for this domain via an external host – lets call it filtermail.com.

You would typically set the MX records for mydomain.com to point to in.filtermail.com as follows:

mydomain.com. 14400 IN MX 10 in.filtermail.com.

And, presumably, you would configure filtermail.com to send your sanitised, cleaned mail back to mail.yourdomain.com and set your exim config to accept all mail locally for your domain. Great, so now you are happily filtering your mail for spam – but wait… some sneaky monkey decides to try sending spam directly to mail.mydomain.com, and your exim happily receives it, because exim isn’t aware of the DNS settings, and doesn’t know any better.

So, we need to tell exim NOT to accept any mail for mydomain.com UNLESS it is coming from, lets say for the sake of argument, out.filtermail.com. Let’s say that out.filtermail.com has an IP address of 194.189.242.1. Read More…