On 24/09/2020 13:43, Jim Jackson wrote:
> Mostly. Somemail servers do a reverse IP lookup and see if it matches your
> envelope From domain.

Yes, this is an annoyance. There are two ways round this: (1) Change
your server's SMTP From domain to be the same as your static IP's PTR
hostname, and (2) ask your ISP to change the reverse DNS to be the name
of your mail server.

Option 1 is a bit embarrassing if anyone notices (e.g.
"host-46462.static.bugtown.myisp.net" isn't too cool as the name of your
mail server) but I don't see any technical downside, although DMARC
might perhaps be an issue nowadays.

I can confirm that I done option 2 in the past to good effect (on
Eclipse Internet in case anyone cares) but I've not tried to do it more
recently. I suspect that some ISPs might be a bit choosy about this
nowadays just in case you're a spammer.


--
Mark Rousell