Mailing List Message #93557
From: Tom Rymes <>
Subject: RE: Mail being delayed on a busy CGPro server
Date: Fri, 28 Dec 2007 14:42:44 -0500
To: CommuniGate Pro Discussions <>
X-Mailer: CommuniGate Pro MAPI Connector 1.2.12/
> Niall O Broin wrote:
> > I have previous sad experience with using a general purpose CGPro
> > server for mass mailing. The server worked fine, but people
> using it
> > as an SMTP server weren't at all happy because their
> outgoing mail got
> > caught up in the rather full outgoing queue. Eventually, in
> that case,
> > we moved the mass mailing function to a dedicated CGPro server, and
> > users were happy again.

Lyle Giese wrote:

> The issue becomes if you allow too many simultaneous outbound
> SMTP connections.  You can flood your Internet bandwidth and
> it will actually take longer to send email when the system
> gets into this condition.  And it can adversely affect
> inbound as the server's responses get caught in the flood of
> outbound traffic.
> I have 3 Mbps bandwidth(both ways) and limited SMTP to 5
> simultaneous outbound connections.  This limited SMTP from
> flooding the Internet bandwidth, while allowing other traffic
> to share the bandwidth.  Your mileage may vary.  When you
> have a large number of messages in the outbound queue, they
> will go out faster with fewer channels allowed than with a
> high number of outbound channels allowed.

Well, this is not necessarily the problem. If IMAP, POP, and other traffic in and out fo the server is not having performance problems (ie: only the SMTP traffic seems backed up and retrieving mail is as fast as normal), then the problem could be that the server is simply taking too long to send the outgoing spam, ahem, mass-mail. <smirk>

If this is the case, you might investigate the settings for the number of processors handling message enqueueing and dequeueing. Also, if the number of outgoing channels for SMTP is limited, your users' outgoing messages will be delayed as they wait for the mass-mailing to be sent. I would (Contrary to prior advice) consider increasing the number of outgoing channels, provided that your bandwidth will support it.

Perhaps someone else can confirm if there is a way to specify to the server that the mass mailing is a lower priority and that regular user's messages should be processed first. Maybe by submitting the mass-mail to a separate SMTP process on a different port?


Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster