Good morning, this is my first post here so please be gentle with me.
Please accept my apologies for the length of the post. I've done some
research but get mixed, missing and contradictory views so I could use
some professional input.
For a few years I have been using Postfix largely because I inherited
the 'skills' from a support based role where it made up a large portion
of an anti-spam appliance I worked with.
Recently I've started to look for reasons to justifiably try Exim and
look at what it can do 'better' or 'differently' to Postfix.
I'm guessing this list is watched by Exim experts who are very
intelligent. Ultimately it comes from the Cambridge University stable
and I'm wondering if I can get a few quick 'yes'/'no' type answers to
help dispell some myths and give me a prod to install it and look at it.
I'm told that Exim has a steep learning curve and 'ordinary' admins
struggle with it when compared to Postfix - does anyone here hold a view
on that?
My cursory searches suggest that Spamassassin can be implemented with
Exim but I'm keen to know if it's possible to get Exim to reject
messages that Spamassassin scores at 'x' during the SMTP session {rather
than after accepting the message} Currently I can get Postfix to do this
but have to plug a slightly buggy and exploitable milter into it to do
this. I'd be very keen on an MTA that could do this easily - does Exim
tick this box?
I would like to make use of Bounce Address Tag Validation. I've seen it
in my logs but it appears that Postfix has only an experimental
milter/PD for this - does Exim have a solution for this and is it easy
to implement?
http://en.wikipedia.org/wiki/Bounce_Address_Tag_Validation
Postfix allows some basic header and body checking (but does not really
have an effective way to white list such rules) - does Exim have similar
or better features in this area?
As far as SASL goes with Exim, is it limited to Cyrus or can it use
Dovecot?
Can Exim support 'virtual' domains with this kind of scenario:
Accept mail for catchall@domain for virtual mailbox on the local machine
Accept mail for catchall@domain and relay to a final destination server
Accept mail for x.recipient@domain1 and deliver to local virtual mailbox
Accept mail for y.recipient@domain1 and relay to remote final
destination.
Can I get Exim to archive a copy of all mail that passes through it by
piping it to another indexing program?
How does Exim fair as far as DKIM signing / verification goes?
Finally, I'm guessing and taking as read Exim supports rejecting on
DNSBL's, missing/errors in PTR and invalid recipients (either by looking
to LDAP, a PostgreSQL or MySQL database)
I appreciate that this is a long post with lots of questions. I want to
be 'patriotic' and try an English MTA but need to be sure I'm not going
to get into several months of 'learning' to find that I've gone the
wrong way!
Kind regards
Daniel
