Notifications and the Share Page Functionality do not Work in Confluence 3.5 or Later

Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.

Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.

*Except Fisheye and Crucible

Symptoms

In a 3.5+ instance that was upgraded from a pre-3.5 instance, notifications and the Share Page functionality do not work. Sending a test email from the Mail Server configuration admin page does, as do daily digest and forgotten password emails.

The following appears in the Confluence log files:

1 2 java.lang.ClassCastException: com.atlassian.mail.server.impl.SMTPMailServerImpl cannot be cast to com.atlassian.confluence.jmx.JmxSMTPMailServer

Cause

The internal storage of Mail Servers was changed in 3.5. Old mail servers should have been migrated on upgrade, but if the upgrade process does not complete properly or earlier upgrade tasks fail, the Mail Servers won't be upgraded correctly.

Resolution

From the Mail Server admin screen in your 3.5 instance, delete your existing mail server and add it again with the same properties.

Updated on April 8, 2025

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