Incorrect name keeps appearing in Mail.app account info
From http://kb.mit.edu/confluence/display/mitcontrib/Apple+Mail+shows+incorrect+name+for+email+address:


  Question(s)
  
  How come Apple Mail shows the wrong name when I type my email address in the To or CC field?
  
  Context
  
  AppleMail
  Apple Mail
  Mail.app
  Address Book
  
  The name that shows up in the TO: or CC: field when typing an email address is incorrect.
  (Ex. Joe User  instead of Joseph User )
  
  Solution
  
  Apple Mail pulls the name information from cards in the address book. If there is a card with the email address typed, it will try to use the name on that card. This can be changed by:
  
  
  Open the address book
  Search for the email address
  Click Edit
  Click the name in the card to change it.
  Click Edit again to stop editing
  
  
  Test by trying to create a new message to the email address in question.