[milters] Archive

Lists Index Date Thread Search

Article: 1207
From: Anthony Howe
Date: 2006-10-23 16:11:50 -0400
Subject: Re: Not Selecting the Best MX for Call-Back?

Removal...........: milters-request@milter.info?subject=remove
More information..: http://www.milter.info/#Support
--------------------------------------------------------

Errol Neal wrote:
> Oct 23 13:16:21 mailscanner sendmail[4164]: k9NHCC04004164: Milter:
> from=<gshen@optionsgroup.com>, reject=550 5.7.1 MX 100 'mail.uu.net.'
> [199.171.54.202] for <gshen@optionsgroup.com> not answering
> Oct 23 13:16:21 mailscanner sendmail[4164]: k9NHCC04004164:
> from=<gshen@optionsgroup.com>, size=1107, class=0, nrcpts=0,
> proto=ESMTP, daemon=MTA, relay=smtp2.theoptionsgroup.com
> [65.195.119.253]
> Oct 23 13:23:19 mailscanner sendmail[5168]: k9NHJJLk005168: Milter:
> from=<gshen@optionsgroup.com>, reject=550 5.7.1 MX 100 'mail.uu.net.'
> [199.171.54.202] for <gshen@optionsgroup.com> not answering
> Oct 23 13:23:19 mailscanner sendmail[5168]: k9NHJJLk005168:
> from=<gshen@optionsgroup.com>, size=1455, class=0, nrcpts=0,
> proto=ESMTP, daemon=MTA, relay=smtp2.theoptionsgroup.com
> [65.195.119.253]

I have 21 milters, two do call-ahead and/or call-back. More context 
would be helpful. More logging too:

	verbose=info,trace,dialog

> That MX has a priority of 100...
> 
> [root@mailscanner log]# host -t MX optionsgroup.com
> optionsgroup.com mail is handled by 10 smtp.theoptionsgroup.com.
> optionsgroup.com mail is handled by 100 mail.uu.net.
> optionsgroup.com mail is handled by 5 smtp2.theoptionsgroup.com.

In both milter-sender and milter-ahead, the MXes are sorted by priority 
from lowest (best) to highest (less desireable) and used in that order. 
Some sites, typically universities I've seen, will block outside 
connections to the lowest valued MX at the firewall, forcing use of the 
secondaries. Not a practice I favour.

You should validate the lower MXes by hand first.

> There are two other MXs with a much lower priority. Is there a switch I
> need to pull from this?

If its a call-back, no. If its a call-ahead, possibly depending on 
configuration.

-- 
Anthony C Howe          Skype: SirWumpus                    SnertSoft
+33 6 11 89 73 78         AIM: SirWumpus    Sendmail Milter Solutions
http://www.snert.com/     ICQ: 7116561
     http://www.snertsoft.com/

Lists Index Date Thread Search