I'm a Mac newbie using Apple Mail version 8.2 on Yosemite 10.10.3: I have 5 mail accounts and have noticed that mails sent from any account often get mixed up with sent mails from the same or different accounts. It is a complete mess, e.g. a sent mail can be appended to another sent mail's header from a different account, or, a sent mail can appear in the midst of a group of mails sent to an entirely different address. I have searched but not found anyone else who is reporting the same problem. Please help?