Duplicate emails in Thunderbird

Hello,

I'm setting up a new laptop, I copied all my Thunderbird settings from my PC using MozBackup and everything seemed to go well. I went into TB's settings and checked 'leave messages on server' (I want to keep everything on my PC). When I receive an email I get a duplicate. This has me baffled and I'm not sure where to start looking.

Anyone have any ideas?? Thanks in advance.

 

By checking "Leave messages on server" means you will leave the messages on your ISP's server not your computer. Un-check this setting and the duplicates should stop. Your downloaded messages will stay on your PC in the TB mail program until you manually delete them.

 

Close, what I need to do is to be able to check email on the laptop (this is where the duplicates are showing up) and I want to be able to download (in Thunderbird)and archive the emails on my PC at home. And this seems to work fine except I get duplicate emails on my laptop for every email I receive. This is kind of strange and I hope I explaining this clearly.

 

Whenever I copy my mail files, e.g. Inbox, Sent, etc., I don't copy the equivalent .msf, or "header" files. Those files, which are found in the Profile folder, should not be copied in first place, allowing the program to create new header files, or should be deleted, with the program closed, and, then allowing it to create new header files. Typically, duplicate mail is caused by corruption of the .msf files. The solution is to delete the existing .msf files, with TB closed, and then restarting TB. I never saw duplicate mail if the .msf files were deleted.