[Mailman-Users] Sendmail getting bum rap...

[Jon Carnes]

On Thursday 25 October 2001 13:48, Amanda wrote:
> My fundamental issue with sendmail is that it's not intuitive. 

Sendmail is not intuitive.  Very true, and a very good argument against its 
use.  If you don't mind, I'll translate that statement into "Sendmail is 
overly complex and convuluted."  Very true.  It tries to be an MTA for all 
seasons and all situations.  This makes it somewhat bloated and by its 
sheer volume of possible configurations: intimidating.

It also means that its development and deployment is much harder, and the 
possibility of an exploit creeping in unnoticed is much higher.

> The docs aren't intuitive or even helpful. 

There is a great volume of sendmail documentation.  Some of it is horrible. 
Some of it is great!  I've always found the writing at:
  http://www.sendmail.org 
to be clear and to the point.  Very good stuff.  Very helpful.  Arranged in 
an "intuitive" manner.

> One arrives at optimum system performance not by reading and making
> informed tweaks to the system, but by randomly twiddling and praying
> for the best. In other words, it's basically voodoo,

There are excellent docs on increasing the performance of Sendmail.  
My personal favorite tweak is to get rid of ident:
  O Timeout.ident=0s 

The bonehead default for this is 30 seconds, and since most servers don't 
use ident, you waste 30 seconds waiting for it at each site you connect to.

If you send a message to 500 distinct sites (which don't use ident) then 
the soonest you can expect to be done is 21minutes!

Also for a mail server, you should adjust up the following:
===
# load average at which we just queue messages
#O QueueLA=8
 
# load average at which we refuse connections
#O RefuseLA=12
 
# maximum number of children we allow at one time
#O MaxDaemonChildren=12
 
# maximum number of new connections per second
#O ConnectionRateThrottle=3
===
You should be able to double these easily on a decent server that is mainly 
a mail server.  
The defaults are meant to enable sendmail to run on very low-end systems 
without trouble.