[CentOS] Replacing sendmail with postfix

--On Saturday, September 21, 2019 9:59 PM +1200 Peter 
<peter at pajamian.dhs.org> wrote:

>> I use spamassassin via amavisd-new, with messages going postfix ->
>> amavisd -> second postfix (all via SMTP).
>
> This is a good setup, but you may find that you can eliminate the second
> postfix step there and go postfix -> amavisd-new -> dovecot lmtp. Unless
> you need additional processing specifically from postfix after
> amavisd-new, that is.

I've been doing sendmail -> MIMEDefang -> SpamAssassin/clamd and then 
sendmail -> procmail -> SpamAssassin. Yeah, SA gets run twice, once to 
reject scores > 10 by the milter and then again by each user to incorporate 
their Bayes scores. I'd love to run it only once but haven't invested time 
in figuring out how to do that. But I only have a few users so it hasn't 
been a big enough load to worry about it.

I'm the only one in my family/office doing extensive procmail filtering for 
my own mail, as I subscribe to lots of lists and like pre-filtering it all 
into separate folders. (I probably have 100-200 folders, so my MUA gets a 
workout looking for new mail.) I'd replace the procmail filters with sieve 
ones using Dovecot but I still want SpamAssassin to run first to mark the 
spam for filtering.

(BTW, pet peeve about Thunderbird MUA: It fails to spot new folders I 
create when I add a new procmail filter. I have to go into Thunderbird's 
subscription dialog and force it to reload the folder list. I use an old 
copy of Mulberry in parallel and it always dependably reloads the folder 
list on startup.)