I’ve been toying with cleaning up my email/Inbox Zero and, as a start, would like recommendations for a way to delete duplicate emails. I have accounts from Outlook.com, iCloud and Gmail that I would eventually like to use it with but at the moment it is only the Outlook.com account that I am ironing out. I tried Jolly Roger’s Remove Duplicate Messages utility but that didn’t work. It did detect and delete duplicate emails in Mail.app on the Mac but for some reason these didn’t get deleted server side despite having set Mail.app to remove deleted messages from the server. I hear that Outlook 2016 has a Clean Up feature but, alas, it is only available on the Windows version of the app.
As an aside, I was a little taken aback by the cracks in Mail.app in dealing with Outlook.com emails. I had to rebuild the mailbox while dealing with anything more than a handful of emails or it would lose track with the server. I have been pleasantly surprised so far with Outlook 2016 for Mac.