Hello,
I’m experiencing a strange problem and can’t find a solution.
I have my own SMTP server. Normally, using port 25 works, but it is blocked for security reasons.
I configured STARTTLS/SSL and it works fine. BUT… Now I have 465 and 587 working.
Proxmox Backup Server (PBS) and Proxmox VE do not send emails automatically.
Anonymous TLS connection established from unknown[xxx.xxx.xxx.xx]: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256
2025-08-18T15:16:47.442587-04:00 smtp-01 postfix/submission/smtpd[8766]: disconnect from unknown[xxx.xxx.xxx.xx] ehlo=2 starttls=1 quit=1 commands=4
Who is a normal message when a user dont authenticate.
I have set up the SMTP account and port in the interface, and the test button works perfectly.
I also configured Postfix manually, and it works as expected — in fact, everything works when running as the root user.
I realized that backup jobs are executed by another user (backup).
Even after giving this user the proper permissions, the jobs still fail.
The problem: None of the jobs can send emails automatically. They cannot authenticate because they do not seem to use the credentials configured in the PBS/Proxmox interface.
Has anyone encountered this issue or found a solution?
Thank you in advance.
DATA: Can't use the user/password even in POSTFIX and PROXMOX.
I’m experiencing a strange problem and can’t find a solution.
I have my own SMTP server. Normally, using port 25 works, but it is blocked for security reasons.
I configured STARTTLS/SSL and it works fine. BUT… Now I have 465 and 587 working.
Proxmox Backup Server (PBS) and Proxmox VE do not send emails automatically.
Anonymous TLS connection established from unknown[xxx.xxx.xxx.xx]: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256
2025-08-18T15:16:47.442587-04:00 smtp-01 postfix/submission/smtpd[8766]: disconnect from unknown[xxx.xxx.xxx.xx] ehlo=2 starttls=1 quit=1 commands=4
Who is a normal message when a user dont authenticate.
I have set up the SMTP account and port in the interface, and the test button works perfectly.
I also configured Postfix manually, and it works as expected — in fact, everything works when running as the root user.
I realized that backup jobs are executed by another user (backup).
Even after giving this user the proper permissions, the jobs still fail.
The problem: None of the jobs can send emails automatically. They cannot authenticate because they do not seem to use the credentials configured in the PBS/Proxmox interface.
Has anyone encountered this issue or found a solution?
Thank you in advance.
DATA: Can't use the user/password even in POSTFIX and PROXMOX.
