Mass Mailing help needed (Paul Rubin)

[William Park]

A.M. Kuchling <akuchlin at ute.mems-exchange.org> wrote:
> In article <mailman.1019553582.18769.python-list at python.org>, 
>        Graham Ashton wrote:
>> With that approach you have to open one TCP connection per message. This
>> is expensive, especially as your SMTP daemon should be doing all sorts
>> of checks on your IP to see if it'll happily accept mail from you. Not
> 
> It's certainly possible to send multiple messages over a single SMTP
> connection, and IP checks can be loosened by tweaking the SMTP
> server's configuration.  For example, it would be easiest and most
> secure to disable address checking on connections from localhost, and
> then run your bulk mailing software on the same machine as the SMTP
> server.  We've had to do this in order to make a 1700-member mailing
> list run acceptably; without disabling the address checks, each
> message to the list resulted in 1700 DNS lookups before the message
> was even accepted.

If 1700 recipients are all different domain, then Sendmail will check for
MX or A record.  But, you can run your own DNS server (either cache-only or
forward-only) to speed up lookup for previously encountered domains.

-- 
William Park, Open Geometry Consulting, <opengeometry at yahoo.ca>
8 CPU cluster, NAS, (Slackware) Linux, Python, LaTeX, Vim, Mutt, Tin