[Mailman-Users] Optimizing sendmail

Chad M. Stewart Chad at Balius.com
Mon Nov 12 17:42:46 CET 2001

Due to the nature of how sendmail works I find that a site can get messages 
out faster if they have multiple processes running delivering mail to a 
small number of recipients.

When I was running sendmail and majordomo together I used a 3rd tool, 
bulk_mailer.  majordomo submitted one message to bulk_mailer.  bulk_mailer 
would split the single message into multiple messages with N recipients per 
message, where N is a number I set.

Now I'm using mailman to run the list I still employ the same logic.  If I 
let mailman give sendmail one message with 200+ recipients it would take 
hours to get that single message out.  The problem is that if recipient 50 
takes 2 minutes to connect and another 5 minutes to deliver that slows down 
delivery for all recipients after number 50.  Certainly more than just one 
address on the list will slow down delivery.

By having more sendmail processes with a small number of recipients per 
process allows for faster delivery. In my mailman configuration I set 
SMTP_MAX_RCPTS to 10.  Each site is unique and thus will have to find the 
right number for themselves.


--On Friday, November 09, 2001 3:47 PM -0500 Jon Carnes <jonc at haht.com> 

> http://www.sendmail.org
> Sendmail is extremely tweakable - so much so that the default is for a
> low-end server.  You can easily increase speed and efficiency by tweaking
> the values in your /etc/sendmail.cf file.
> The best tweak is to remove that ident crap call by setting:
>   O Timeout.ident=0s
> Otherwise 99% of your connections wait for 30seconds before actually doing
> anything...
> Jon Carnes
> ----- Original Message -----
> From: "Steve Dinn" <sdinn at spine.cx>
> To: <mailman-users at python.org>
> Sent: Friday, November 09, 2001 1:01 PM
> Subject: [Mailman-Users] Optimizing sendmail
>> I know that the question I'm about to ask doesn't relate specifically to
>> mailman, but I thought that I'd be in the company of people who are more
>> qualified than most to answer it:
>> In what ways can sendmail be tweaked or otherwised optimized for sending
>> out a large number of emails at once?  This is the case everytime someone
>> posts to a list withi lots of subscribers, so I thought it relevant.
>> Anyone?
>> -Steve.
>> --
>>  Steve Dinn                       email:  mailto:sdinn at spine.cx
>>                                     www:  http://spine.cx/
>>             Join my fight against Subway's new cut!
>>                   http://spine.cx/subway/
>> ------------------------------------------------------
>> Mailman-Users maillist  -  Mailman-Users at python.org
>> http://mail.python.org/mailman/listinfo/mailman-users
> ------------------------------------------------------
> Mailman-Users maillist  -  Mailman-Users at python.org
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