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Veeam does not send automated emails but email test configuration works

  • July 2, 2021
  • 26 comments
  • 15679 views

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26 comments

  • New Here
  • August 24, 2026

Hello,

Veeam Agent for Windows – Email notifications fail after Windows Update

Note: This is an ongoing issue — still occurring on current Windows Server and current Veeam Agent builds as of August 2026. Expect it to reappear after future cumulative updates.

 

Symptom

Job log shows: Failed to send email notification: Unable to connect to SMTP server because of invalid credentials or connection settings.
The built-in SMTP test succeeds. Job itself completes with Success. Send-MailMessage from the same machine with the same credentials works. Started after a Windows/.NET cumulative update.

Cause

The stored SMTP configuration (including the cached server certificate) becomes stale. Veeam only re-validates it when the settings actually change — re-entering the same values is not enough to trigger it.

Fix  – Quick workaround (try this, no reinstall)

  1. Install pending Windows Updates, make sure the Veeam Agent is on the current version.
  2. Switch the SMTP settings to a different provider/account, save, run a backup, confirm the mail arrives.
  3. Switch back to the original SMTP account, save, run a backup again.

Changing the provider forces Veeam to discard the stale configuration and re-validate the certificate. That is what actually fixes it — re-typing the same credentials does not.

 

Greetings, R