[Zope] 'Offline' mailhost

[Jan H. Haul]

Terry Kerr wrote:
> 
> Chris Withers wrote:
> 
> > Hannu Krosing wrote:
> >
> > > Also you could send just one message to all the recipients instead of
> > > sending individual messages.
> >
> > Urm, they could be pretty unfriendly mail messages if they're being sent
> > to a coupla thousand people. The bandwidth dcoming out of your server
> > alone would be far higher than it needed to be :-(
> 
> How would the bandwidth change??

Well, suppose you send a message of, say, 2 KByte (about one page
of typed text) to 1,000 recipients. You'll make about 1,000
connections to the recipients' MX hosts. 

Each of these will be around 42 KByte large.

Huh? Why that? you ask.
Because in the header of each mail, the whole recipient list will
be listed under To: or Cc: (I assumed 40 bytes per address as a
roundabout figure). In the envelope (what the SMTP protocol
*uses* to deliver the message, only one address will be used, the
body To: list is mainly for the recipients' use (to show them who
else got it).

Besides, there are other problems why you will want separate
mails:

- privacy: You would not like to have "your" recipients end up on
other people's mailing lists
- stability: When E-mail bounces, you would like to hanle it
intelligently, like trying this address once again (as it could
be a temporary outage) and take the address off the list if it
still bounces a week or so later
- stability again: You woulld not like to be blacklisted as
either a spammer or clueless by the recipients' postmaster :-)

I would probably use a stable MTA (like qmail, which has good
mailing list processing software, or postfix) for the job.

Cheers,
Jan