Mail 7.3 corruption - ghost name

I have three (3) email accounts (MOG, Olive and Broker) hosted on my MacBook Pro (10.9.5) running Mail 7.3 (build 1878.6). I administer my own mail servers at Dreamhost.

Strange things are happening:

1. In the Olive account, my address line is corrupted on incoming and outgoing mail. The name of someone else (a recent correspondent) is inserted in front of my email address. This only happens on the Olive account.

2. I deleted an email address in the Broker account, then tried to create a new one. (The address and password were set up on my Broker mail server and I was able to log into mail using web.) Although I think I have all the Mail 7.3. settings done correctly (same as the other accounts), my log-in attempts to mail.broker.com fail. It seems to be on the Mail 7.3 side.

In truth, lots of strange things have been happening since I upgraded to 10.9.x - not the least of which is a _huge_ demand for processor cycles.

Any Help Appreciated.

Mike