Issues with SMTP settings

[Ajegon]

Dear Readers,

I'm trying to configure SMTP notifications on the backup server in my homelab, however I keep getting authentication failed error when doing a test message.
I configured it with a Protonmail SMTP submission and im sure the credentials should be good.
https://proton.me/support/smtp-submission

This is what I found in the Satalite logging for my user account:
[CReportMailer] Sending e-mail notification, server 'SMTP Server 'smtp.protonmail.ch', port '587', timeout '100000', use ssl 'True'', to 'user@test.com'
[05.05.2025 16:48:50.974] <18> Info (3) https://smtp.protonmail.ch:587 certificate thumbprint 634F09043D3546A15FB5ACB803262860F8B55413

Is there any other logging I could check to see whats going wrong?

I hope you might be able to help me along.

Kind regards,
Ajegon

[david.domask]

Hi Ajegon,

We unfortunately will not be able to troubleshoot such things over the forum, so a Support Case is the way to start the investigation as noted in the forum rules and when creating a topic.

Please create a support case and include logs for Veeam Support to review. (Use the 3rd radio button to export logs from hosts, select the Veeam server to export from)

I've not tested with Proton mail, but as I get it they create some temporary SMTP account it looks that is associated with the Proton Mail account but separate. I think the SSL option might be the issue, since I see they use STARTTLS which upgrades the connection received to a secure one before sending. Try without the SSL option, but if no luck, please create a Support Case as noted, and share the case number once created.

Thanks!