Processing large email

Jeff A. Earickson jaearick at COLBY.EDU
Tue Feb 4 18:28:58 GMT 2003


   I suggest setting a maximum message size in sendmail.  The
m4 entry is:

define(`confMAX_MESSAGE_SIZE', `10485760')dnl

for a 10MB maximum, for instance.

The third edition of the Bat Book (O'Reilly's sendmail book) has
a good write-up about configuring multiple sendmail queues and
multiple .cf files to handle queues of different size/speeds.
They give an example of a "fast" queue and a "slow" queue.
Every email gets one chance to get processed with the fast queue
options and if it doesn't go out the first time, then it ends up
in the "slow" queue for later retries.  I read thru the chapter
when I had the Bat Book in hand at a book store; I've ordered a
copy but don't have it yet.

--- Jeff Earickson

On Tue, 4 Feb 2003, Tim Sailer wrote:

> Date: Tue, 4 Feb 2003 12:22:13 -0500
> From: Tim Sailer <sailer at BNL.GOV>
> Reply-To: MailScanner mailing list <MAILSCANNER at JISCMAIL.AC.UK>
> Subject: Re: Processing large email
> On Tue, Feb 04, 2003 at 05:15:34PM +0000, Julian Field wrote:
> > At 17:02 04/02/2003, you wrote:
> > >I've been using mailscanner with great success for a while, but
> > >every once in a while, the mail queue seems to jam up. Investigation
> > >shows that it's large emails, either attachments, or just text,
> > >but 100MB+. Is there any way (running exim) to either push this
> > >off to another queue, or give the large email a low priority, so
> > >it doesn't get scanned until there's nothing left to do?
> >
> > A large email will only block up one of the child processes. The others
> > will continue scanning other mail. If you run with the default 5 children,
> > then you would have to have 5 huge mails turn up at *exactly* the right
> > moments so as to block all 5 children.
> It happens, trust me. I'm graphing mail latency, and sometimes the
> latency goes up to 40+ minutes. :(
> Tim
> --
> Tim Sailer <sailer at>
> Application Services
> Information Technology Division
> Brookhaven National Laboratory  (631) 344-3001

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