problems with receiving e-mails since upgrading to Proxmox 8.0

[PhDh]

Hello,

For different e-mail domains, e-mail is rejected. The message we get is this (I change the personal information with "X's").

2023-10-10T14:50:37.261368+02:00 mail postfix/smtpd[88407]: connect from ns304197.ip-94-23-210.eu[94.23.210.134]
2023-10-10T14:50:37.349123+02:00 mail postfix/smtpd[88407]: NOQUEUE: reject: RCPT from ns304197.ip-94-23-210.eu[94.23.210.134]: 554 5.7.1 <kvs@xxxxxx.be>: Recipient address rejected: Rejected by SPF: 94.23.210.134 is not a designated mailserver for info%40ph.belgium.be (context mfrom, on mail.xxxxxxxxx.be); from=<info@ph.belgium.be> to=<kvs@xxxxxx.be> proto=ESMTP helo=<ns304197.ip-94-23-210.eu>
2023-10-10T14:50:37.349207+02:00 mail postfix/smtpd[88407]: using backwards-compatible default setting smtpd_relay_before_recipient_restrictions=no to reject recipient "kvs@xxxxxx.be" from client "ns304197.ip-94-23-210.eu[94.23.210.134]"
2023-10-10T14:50:37.405797+02:00 mail postfix/smtpd[88407]: disconnect from ns304197.ip-94-23-210.eu[94.23.210.134] ehlo=1 mail=1 rcpt=0/1 data=0/1 rset=1 quit=1 commands=4/6

In another post we read the same:
https://forum.proxmox.com/threads/s...m-microsoft-hotmail-for-some-messages.131063/

I guess it is the same problem but we didn't had that prior to version 8 and we have it now for some e-mail domains (big companies).
How can we solve this? Checking the tracking center every day and add the domains to the smtp whitelist is not a good solution. Removing SPF checking is also not a good solution.

Thanks.

 

[dcsapak]

How can we solve this?

hi, you cannot solve this really on your end. if another company sends mail from an ip not allowed to send (per *their* spf policy) this is not something you can fix.
you basically listed the options you have on your side, either ignore the spf policy (i.e. turn off spf checking) or whitelist the senders that have a bad configuration...