How can i relay all outgoing mail not for my domain to an external relay that I have setup on a vps with the correct reverse lookup address?
Something like the green lines here:
GPT5 tells me:
is there a problem receiving emails for example.com on a dynamic ip?
Yes — there can be problems.
Deliverability: Many MTAs and anti-spam services reject or defer mail to hosts in dynamic-IP ranges or IPs listed on PBL/RBLs, so other MTAs may refuse to deliver to your MX.
...
Also
Actual behavior depends on each sending operator’s configuration; being listed in a particular RBL/PBL or lacking PTR/DNS is what causes rejection/deferral, not an inherent property of every sender.
For authoritative, actionable remediation: host MX on a static IP with proper PTR and publish SPF/DKIM, or place a static relay (smarthost/MX) in front of your dynamic host.
I'd lose much of the benefit of pmg using a simple postfix on the vps as a relay.
I'm reluctant to install pmg on the vps as it already hosts a website and that would complicate maintenance and security significantly.
The best solution seems to be providing a static ip. Hopefully getting a reverse dns from my isp won't be too difficult.
