DragonFly kernel List (threaded) for 2007-03
Re: first stab at simple mailer
Simon 'corecode' Schubert wrote:
Rahul Siddharthan wrote:
But you still need to efficiently queue the mail for
forwarding. Youqmail does it...
can't just make separate connections to the target for each
The claim is that making separate connections is usually faster (fewer
round-trip delays) because of how SMTP works. It does use more
bandwidth but this is unlikely to be significant on most sites,
most of the time.
These days however, when people send attachments megabytes in size (or
viruses do it for them), I don't know whether that claim is still
1. I think it *is* unfair towards the receiving MX to send the same mail
2. I think it is *negligible* for locally generated, private + cron mails.
3. not trying to aggregate mail delivery on one MX makes the code *SO
MUCH EASIER*. seriously. think about what you need:
a. central coordination instance
b. MX/A lookups for all domain parts of all mails
c. choose one MX
d. now find all mails which could potentially be sent there
e. weed out rejects
f. start over
point is, you can't say "hey, they have the same MXes", because
different domains could share only one MX out of three, for example.
you have to check for every MX connect which other mails could be
delivered there. definitely not a necessary option for the first round.
Feel free to use these addresses for testing your queing and retry rules on
multiple recipients et al:
Typical daily logs are a good test send, as like it or not - some can be
perceived to have spammish characteristics.
The postmaster address should be found to accept domain-literals, i.e. addressed
to email@example.com, IF there are no other addressees on such a message
(illegal for bounces). The others will not.
- it is a server dedicated primarily to MTA R&D, (Exim at present) and I can
give you log extracts if the rejection messages you will certainly get are not
It should become apparent 'real soon' that building a reliable MTA in the 'spam
age' - one that doesn't resemble a zombot - is a seriously non-trivial exercise.