[SOLVED] Emails to non existent users (addresses)

Walhalla

Member
Jan 26, 2018
44
4
13
52
Hi,
how to prevent accepting emails to users (addresses of a domain which is handled by the machine via transport) who do not exist on the final recipient machine? Spending resources / traffic welknown that it will end in an bounce from the final destination ("User unknown").

Regards
 

dietmar

Proxmox Staff Member
Staff member
Apr 28, 2005
17,125
526
133
Austria
www.proxmox.com
You can enable receiver verification at "Configuration/MailProxy/Options/VerifyReceiver". I suggest to set that to 450 (reject with temporary SMTP error).

Please note that this only works if your final email server rejects mail to unknown users too (The final server need to reject at SMTP level, as opposed to accepting it and send a bounce later).
 

Walhalla

Member
Jan 26, 2018
44
4
13
52
Please note that this only works if your final email server rejects mail to unknown users too (The final server need to reject at SMTP level, as opposed to accepting it and send a bounce later).

Unfortunately there are several mailservers which accept first. Not everytime it is known what product other people use and/or how they configured their machines. Therefor postfix has several other mechanisms - but obviousely none of them is used. Will generate many bounces / backscatters and ends up in blacklisted machines.
 

Walhalla

Member
Jan 26, 2018
44
4
13
52
Do you have any influence what servers other people use and how the configure their machines?
 

tom

Proxmox Staff Member
Staff member
Aug 29, 2006
15,554
925
163
Do you have any influence what servers other people use and how the configure their machines?

In a normal Proxmox Mail Gateway setup, you have full control about your internal email server. If your customers wants to use your filter services, you have to advice them how to setup their Email servers correctly if you want to use Receiver Verification. 550 rejects for unknown users are standard and quite easy to configure.
 

Walhalla

Member
Jan 26, 2018
44
4
13
52
It is not the kind of "Service" everybody else does: tell other people that they have to change their configs if a solution is availlable (but not implemented in PMG). Its not the other users fault.

Dont need to discuss this more. Solved.
 

tom

Proxmox Staff Member
Staff member
Aug 29, 2006
15,554
925
163
The primarily use case of the Proxmox Mail Gateway is protecting your own internal Email Server.

So there are no "other" people involved this use case.
 

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