[CS-FSLUG] using postfix or sendmail to send mail

Frank Bax fbax at sympatico.ca
Thu Mar 12 13:34:48 CDT 2009

Jonathan E. Brickman wrote:
> Your ISP is almost certainly blocking SMTP traffic from its clients; 
> many do these days. It is possible to build your own smarthost, given a 
> more expensive commercial Internet connection explicitly set up for the 
> purpose, but there are more things to do. You'll need a static IP, 
> forward and reverse DNS on that IP, and an SPF record ( www.openspf.org 
> ) to do well. And within 24 months DNSSEC will start to get serious; 
> that will have very interesting ramifications.

If you decide to go with static ip address; you should have ONLY the 
mailserver at this ip address.  If you put the static ip address on a 
NAT router; then you expose yoursefl to different problems.

I recently had to fix a situation where a company had this setup.

A workstation at this site got infected with a spambot.  The volume of 
spam caused the static ip address to be blacklisted; causing problems 
for outgoing email from the mail server.

If you want a static ip as Jonathon describes; that you should seriously 
consider two (or more) static ip address and put mail server on a 
separate ip than the rest of computers at the same site.

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