Running 8.22 on W2K for several years without any issues.
In the past 2 weeks we have been seeing a lot of problems sending to
yahoo mail. What's happening is that the SMTP thread is hanging for 4
minutes until it's timing out. This happens between 5-10% of the time
(the rest of the time it connects to yahoo fine and the email goes
out okay - it doesn't seem related to load). Normally this would not
be a problem, but we send out a large newsletter of which a large
percentage is to yahoo. What ends up happening is almost all the SMTP
threads get tied up waiting for the 4 minute timeout and mail slows to a crawl.
10:16 16:07 SMTP-(66e902260000a1f8) Trying yahoo.com (0)
10:16 16:07 SMTP-(66e902260000a1f8) Connect yahoo.com [216.39.53.1:25] (1)
** note 4 minute hang time - the smtp delivery thread is unavailable
during this time **
10:16 16:11 SMTP-(66e902260000a1f8) rl-recv: Blocking call cancelled
10:16 16:11 SMTP-(66e902260000a1f8)
10:16 16:11 SMTP-(66e902260000a1f8) SMTP_DELIV_FAILED
10:16 16:11 SMTP-(66e902260000a1f8) >QUIT
Problem is occurring across yahoo ip's (i.e. 216.39.53.2, etc....) I
have a couple of tickets open with yahoo but I'm not confident I am
going to get anywhere. If I telnet to them, it hangs about 5% of the
time and I get:
Microsoft Telnet open a.mx.mail.yahoo.com 25
Connecting To a.mx.mail.yahoo.com...Could not open a connection to host:
Connect failed
The other 95% of the time it works fine.
What's interesting is with Telnet, I get this same problem from a
different machine on a totally different IP block and connection so I
don't think it's related to my IP. Seems like an issue with yahoo.
1. Has anyone seen a similar issue in their SMTP log files connection
to yahoo? It's been going on about 2 weeks.
2. I spoke to support and they recommend I increase the number of
delivery threads from 30 to 90 and Maximum Retry Threads from 15 to
40. I ended up increasing it from 30 to 40 and from 15 to 20 (we are
running W2K - was concerned about exceeding the 77 service started
processes discussed here -
http://www.declude.com/Articles.asp?ID=130). The increase did help a
little. The machine is only running about 4-5% CPU when sending mail.
Can I increase this further from 40 on Windows 2000 Advanced Server.
3. I asked support if the 4 minute time out could be changed and was
told it was hard coded. However I ran across this article in the
Knowledge Base - IMail - How to adjust the SMTP service timeout -
http://support.ipswitch.com/kb/IM-20050708-DM01.htm - will this have an effect.
Thanks
Adam
