[CentOS] Recommend Mail Server

Mon Nov 23 17:36:43 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Gilbert Sebenste wrote:
> On Mon, 23 Nov 2009, Ron Loftin wrote:
> 
>> As others have already suggested, consider Postfix.
>>
>> I'm putting in my $0.02(US) so I can add my experience when I first had
>> a need for a decent MTA.  I had used Sendmail in the past, but I didn't
>> want to fight with the arcane syntax of the config files, and at that
>> time the add-on management tools and scripts were not nearly as friendly
>> to a beginner.
>>
>> When Postfix was suggested to me, I started reading the docs on their
>> Web site, and discovered that the learning curve is nowhere near as
>> steep as it is with Sendmail.  So far, Postfix has done everything I
>> have needed, and with a LOT less pain.
>>
>> As always, YMMV.
> 
> +1. Let me throw in something else. If youa re sending more than one email 
> at a time (to more than one person simultaneously), Postfix will beat 
> Sendmail. It can handle high loads better than Sendmail as well. Is it the 
> fastest MTA out there? Doing some Google Fu some time ago, it's right 
> there with the very fastest ones. For my job, I need to send out emergency 
> notifications to 400 people at once. With Sendmail, that took over 7 
> minutes.

That doesn't make any sense unless you have a backed up queue with at 
least many thousands of messages - in which case you should tune 
sendmail to use multiple queue directories.

> With Postfix, that takes seconds, and mostly because of the 
> "handshaking" with the downstream host.

SMTP handshaking has to follow standards.  The difference must really be 
in DNS lookup time.  Sendmail does several more DNS lookups per delivery 
than postfix, but unless something is broken, DNS should be fast and 
certainly shouldn't account for 7 minutes on 400 messages.

> If it's fast, I haven't even got 
> time to send the message, get to a command prompt and type "mailq" and see 
> it leaving the outbox queue...because it is already gone!

That should be the same for sendmail.

-- 
   Les Mikesell
    lesmikesell at gmail.com