Dupe Checker

Dupe Checker

A dupe is a message with the same message-id that arrives for the second time.

This can happen due to multiple reasons:

  • the spam sender has your mail address multiple times on his list and sends out spam with the same message-id
  • you get messages from a mailing list with multiple accounts
  • you changed your Outlook account settings and Outlooks thinks that it needs do download all messages again
  • ...

The Dupe Checker has an expiration age for cleaning old message-ids.