(21-07-2017, 04:01 AM)kyberkhrime Wrote:

Quote:The PTR record for this IP points to mail.z3bra.org. I tried adding another PTR record for the virtual domain, but it's still propagating and I'm not sure an IP can have multiple PTR records.

Technically you can, practically this wouldn't be a good idea, because it would work as round-robin, giving a random PTR-record back every time. Does your virtual domain have an A-record? If not: Set it. That could be it.

Anyhow my provider doesn't let me add multiple PTR records. I realised though that my PTR was not exactly set to "mail.z3bra.org", but rather "orbb.z3bra.org" ("mail" is a CNAME for "orbb" of course). So I changed that to explicitely return "mail.z3bra.org".

My virtual domain is set in the exact same way as the primary domain (mail ---(CNAME)--> orbb), with the MX set to "mail". So yeah, I have an A record for it as well.
What seem to be confusing for other SMTP server is the fact that my address is user@domain.alt, but the HELO sent by my server is "mail.z3bra.org", which is different from the origin. The mail-tester venam linked doesn't report this as an issue thout.

(21-07-2017, 04:01 AM)kyberkhrime Wrote:

Quote:I'll setup DKIM/DMARC then, as it's the last point I can improve.

Setting DKIM up isn't a bad idea, but especially for DMARC I'd recommend thoroughly reading about it beforehand. Because it's not a simple solution to problems and comes with a whole set of its own.

I had DKIM setup already, and it's now enabled again. This is indeed a clusterfuck to understand/setup, but seems to be used (required?) by a lot of wild mail servers, so I guess I'll keep it.
For DMARC, I need to make another test now that the DNS has propagated my TXT record for it. I don't understand a single bit of it though, so I hope it will work on first try. Doing back-and-forth testing with DNS is a huge pain in the neck...

EDIT: Here we are: https://p.iotek.org/u60.png