I have a new computer with MS office +outlook. Win10  mail will not save sent and deleted messages from ISP PlusNet. I have tried POP and IMAP settings, deleting and reloading the accounts, set download to anytime and have done a complete reset on my computer. 

My Livemail account saves sent and deleted mail OK. I have spoken with plus net who do not know the solution.

I really like the Win Mail app it is such a shame it has this problem.

David Gealy