[SOLVED] E-Mail Notification only working for Testmail

[aKoR]

I'm experiencing some weird behaviour with my freshly installed proxmox backup server and it's notifications.
I have create a new notification target of type smtp using my smtp-relay.
When sending a testmail everything works as expected. I recieve the mail on my outlook.com account without any problems.
The relay is beeing used for other services without issues as well.

When PBS triggers a notification for prune or gc for example the mails are not working.
I only recieve an error mail from the backup server on my outlook.com address:


Why are the testmail and the errormail behaving different to the production mail?

EDIT:

I figured out what is happening:

Even though i disabled the mail-to-root notification target and remove it from the default-matcher it still gets beeing used.
As it's using sendmail it's taking the postfix-default-config which makes it send the mail directly with my personal IP instead of my smtp-relay.

Test notification used the relay as it should.

Question now is:

Why is it beeing used even though its disabled and not linked in the default-matcher?



Hope someone can clarify this for me

Regards
Alex

 

[wbk]

Hi aKoR,

I have no reply to your question as to why the testmail succeeds while the real notification mail does not come through. Perhaps the test only has plain text, while the notification has an URL to documentation for troubleshooting or details. In that case, Microsoft may guess that this URL is spam. There is no way to get a confirmation from Microsoft though.

Your best option is to avoid sending anything to, through, via or from Microsoft servers.

The second best option is clicking the link in the helpful message, https://check.spamhaus.org/results/?query=188.193.34.128, and follow the instructions.

 

[aKoR]

Hi,

that has nothing to do with Microsoft at all. PBS is somehow sending the mail with my home IP address directly which is totally fine to be blocked by spamhaus.

The question is how this comes and why it behaves so weird. It should use my relay for any mail, it just doesn't do it and tries to directly send it which doesn't work (and should not work!!).

 

[aKoR]

I figured out what is happening:

Even though i disabled the mail-to-root notification target and remove it from the default-matcher it still gets beeing used.
As it's using sendmail it's taking the postfix-default-config which makes it send the mail directly with my personal IP instead of my smtp-relay.

Test notification used the relay as it should.

Question now is:

Why is it beeing used even though its disabled and not linked in the default-matcher?

View attachment 86687


The question is why is this and how can I prevent that behaviour?

 

[aKoR]

Found the solution in this post:

S

[SOLVED] Thread 'Proxmox not using SMTP settings'

Apr 18, 2025

Hello there,

I have configured both of my proxmox nodes to use my internal SMTP server and set the default-matcher rule to use it.
But day after day I see emails at my inbox where both PBS are using my public IP trying to connect to my SMTP server (which also uses a different public IP):

This is the mail system at host proxmox2.hks.lan.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your...

• showiproute
• Replies: 4
• Forum: Proxmox Backup: Installation and configuration

The notification mode of the datastore has to be changed.