I'd very much like to move my (Postfix) mail server, which currently resides
on a (static IP) end-luser broadband line, to some VM in the cloud someplace,
and then use something like fetchmail to poll that periodically to pull
down all mail for my several domains and then have fetchmail re-inject
all of those mail messages into the local Postfix. The plan would be to
get all this running and then give up my local static IP here, exchanging
it for a dynamic one instead. (This will save me a tiny bit of money on
my monthy local ISP bill.)

Googling for options just now, it sure sounds like ODMR/ATRN would fit
my needs nicely, however I can't quite make out whether any of this
ODMR/ATRN stuff has ever actually been implemented in Postfix or not.
Has it been?

Regardless of whether it has or not, if anyone wants to suggest or recommend
any alternative solution(s) I'm all ears. I am open to anything that
will get the job done. My only real requirements for a solution are:

1) Must support unlimited email addresses per each recipient domain.

2) Must preserve envelope sender information.

In general, speed is not an issue, but security most certainly is.

That having been said, I am not eager to use Jakob Hirsh's odmrd because
that SMTP server is written in Perl, and I've been known to be DDoS'd
from time to time. So I'm loath to leave anything written in Perl running
on any outward facing port. It's just way too easy for an attacker to
run the CPU usage up to 100% and keep it there if one does so.

Looking forward to info on Postfix support for ODMR or alternatives thereto.




By Kevin A. McGrail at 06/09/2019 - 16:56

Well, first, my firm's commercial Raptor anti-pam solution supports
smarthosting for outbound and inbound on an alternate port.  Add any
dynamic DNS solution and you are good to go.  Plus you get the best
business anti-spam solution.  Happy to chat more about pricing. 

But that leads to my answer.  You can just setup a box on a VM with a
static IP and do smtp authentication for smarthosting through that box
and use it as a relay for your domain on an alternate port using Dynamic
DNS.  No need for fetchmail or anything like that.


On 6/9/2019 4:42 PM, Ronald F. Guilmette wrote:


By Antonio Leding at 06/09/2019 - 16:55

Hey rfg,

Just curious…any reason to not use use the could-based Postfix server + something like Dovecot and then have your clients access that directly? I have this now for at least 20 domains and it works awesome.

I’m not understanding why the need to relay the mail to your local Postifix instance…I’m sure there is a good reason but I’m just not seeing as yet…