Click to expand.The root causes for getting duplicate emails in Outlook 2011 Mac are: Clash among rules which are configured with bad settings Lost connection with email server due to maintenance Or Outlook database is corrupted In case of first issue, you should check the rules again as well as remove duplicate accounts. For sever related issues, contact with network administration.
In case database file is corrupted then Outlook user has responsibility to re-build the database. Outlook Mac 2011 database format is OLM file. Sometimes, it got corruption due to unknown error. In this situation some alternative ways are available like OLM repair methodology. In my knowledge, you can try Stellar Phoenix OLM repair i.e.
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Jul 31, 2011 - Duplicates Remover for Outlook deletes duplicate contacts, notes, tasks. The web app is compatible with all Windows PCs and Macs, iOS,. Delete Duplicate Contacts from Outlook, Mac, Gmail and Google Apps address books with the Scrubly. Update your contacts with Facebook, Twitter and LinkedIn contact data.