SPF on downstream server fails


Oct 20, 2021
Dear readers,

I am trying to see if i could implement this solution for our customers, this could save me a lot of time with different mailservers to
maintain. Everything was pretty simple and straightforward, and it looks like it is doing great.

I do however have an issue now. Upon testing the email from Gmail for instance, it goes trough the PMG as expected. However on the downstream server
i get an SPF softfail for gmail. (of course this is correct, since the sending mail server is now the PMG server, which is not in the Google list)

Error is : (Received-SPF: Softfail (domain owner discourages use of this host) identity=mailfrom; client-ip= etc.etc.)

The MX record of the test domain point to the test PMG and works ok.
the PMG delivers correctly to the downstream server without any issue.

That means, my only problem now is that is softfails for domains with SPF set, because Google (e.o.) has of course in his DNS records the SPF entry.

Apart from this, i think it is a great solution, is there any work around ? (and i don't mean disabling SPF checking on the downstream servers, since i don't control all of them.
Thanks in advance!
Last edited:


The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!