[SOLVED] Blocking origin domains?

jureffff

New Member
Nov 3, 2022
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I'm trying to find out how to setup blocking of origin domains when emails get forwarded to us. For example - say I forward everything from my Gmail account to the domain where I use Proxmox Mail Gateway. I don't want to block the specific gmail address, but I do want to block an email which came to said gmail from example@example.com. Is there any way to have Proxmox block email from specific originating domains?
 
This depends how the forward is done in the first place - two options (more are possible):
* mail gets 'bounced' - the envelop-sender remains the original sender (example@example.com) and the mail is just addressed on the envelop to your domain - this is not so common these days (IIRC), since this breaks SPF and other mechanisms to prevent such things (someone else (gmail) sending mails for example@example.com)
* the mail gets 'forwarded' with yourmail@gmail.com as envelope sender - usually then it writes the original sender in a header...

-> check the logs of such a forwarded mail, and the mail headers of such a mail - you can use a Match Field What object to match a particular header content

I hope this helps!
 
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This depends how the forward is done in the first place - two options (more are possible):
* mail gets 'bounced' - the envelop-sender remains the original sender (example@example.com) and the mail is just addressed on the envelop to your domain - this is not so common these days (IIRC), since this breaks SPF and other mechanisms to prevent such things (someone else (gmail) sending mails for example@example.com)
* the mail gets 'forwarded' with yourmail@gmail.com as envelope sender - usually then it writes the original sender in a header...

-> check the logs of such a forwarded mail, and the mail headers of such a mail - you can use a Match Field What object to match a particular header content

I hope this helps!

It helps, all I really needed was a push in the right direction, thank you! Your answer gave me enough info that I think I've set things up correctly, now just to test it out.
 

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