Today I logged into my yahoo mail account on my pc and went to my sent folder because I wanted to send info from an email I sent yesterday to someone else.
So I click into my sent folder and it shows I sent several emails yesterday, but it looks like it sent each email like 20 times or so.. So I wonder if the person on the receiving end got like 20 emails from me?
this has to do with the imap message id, android sends the imap message id surrounded with <> and yahoo mail can't see the message id when it is surround with <> it is a bug on both android and yahoo I suppose.
I have a similar problem with an open source exchange server called zimbra and that is what they have narrowed it down to.