The linux server where exim service is running is under no load.
The system is sending email successfully but is taking a long time to send each email.
Basically if I telnet to localhost port 25 and then I try to send an email from there the response from the server is super slow. The mail application we have running there is taking more than 8 minutes to send 4 emails.
Has anyone confronted this issue before with EXIM and maybe you might now what is the setting that is making EXIM wait so long for something. I am looking at the logs and I cannot see anything indicative of an error. Below a sample of the mainlog:
2009-08-10 07:21:05 H=(aurl.domain.ni) [127.0.0.1] Warning: Sender rate 4.6 / 1h
2009-08-10 07:21:29 1MaTsX-0000mw-Oe <= stgbouncing@theperfectplace.net H=(aurl.domain.ni) [127.0.0.1] P=esmtp S=22003 id=67402024.1249906753667.JavaMail.root@aurl.domain.ni
2009-08-10 07:21:54 SMTP command timeout on connection from (domain.com) [127.0.0.1]
2009-08-10 07:22:42 1MaTsX-0000mw-Oe ** thegroupofbouncing123@earthlink.net R=lookuphost T=remote_smtp: SMTP error from remote mail server after RCPT TO:: host mx3.earthlink.net [209.86.93.228]: 550 thegroupofbouncing123@earthlink.net…User unknown
2009-08-10 07:22:42 1MaTti-0000nM-3b <= <> R=1MaTsX-0000mw-Oe U=mailnull P=local S=23089
2009-08-10 07:22:42 1MaTsX-0000mw-Oe Completed
Best Answer
The server appears to be doing throttling which might affect you if you are testing from one IP:
Often issues like this are related to poor DNS. Exim does a lot of resolution during processing mail. Check the DNS config on the Exim server. Check the performance on the DNS server it is using.
Is the server doing any DNSBL processing? I'm often asked to look at servers exhibiting poor performance and it turns out they are using DNSBLs that have been retired, meaning lookups are timing out.
Try running exim in debug on the server to see where the problem is. The following will run an Exim daemon on port 26, staying attached to the console and printing lots of debug:
Then telnet to tcp/26 instead of tcp/25 and test as you had been.