TCP 3905
Synopsis
- TCP port 3905 is used by mupdate, the Cyrus IMAP “Murder” mailbox update service.
- The cyrus-imapd software uses this port in clustered Murder deployments, where frontend IMAP servers contact the mupdate master on 3905 to locate and synchronize mailbox locations across backend servers.
- This appears in real-world Cyrus-based mail systems, including enterprise and university deployments and groupware stacks like Kolab that use Cyrus IMAP with Murder.
Observed activity
Last 30 days
Detailed chart