Weird Mail Problem

Question

I have about 8 accounts running in Mail, 5 of them are my own with different servers, dot mac, aol, private domain name, etc. Naturally, under user name I put my own on each of them, suddenly, Mail can't seem to tell what Mail is supposed to go where. It's pretty much hit or miss which account any email will land in (the 3 not in my name have no problem). It never occurred to be this would be a problem because I assumed where mail went was due to the actual address, not my name.
I went in and deleted all names so it would only use the mail address for ID and that hasn't helped because Mail is still holding a memory of the accounts under my name. That part where you can just type the first letter of an address and it gives you all the choices that have been used before.
Removing preferences doesn't work, that totally erases ALL accounts. I tried rebuild mailboxes and that didn't help. How can I flush out the old names so that Mail stops using my name and mixing the mail up.

Answer 1

The FULL NAME and USER NAME for an email account are
not one in the same and are not interchangeable when
trying to describe a problem with the Full Name used
for an email account.
Sorry, my mistake. I had just looked at it and could of sworn it said User Name and not Full Name. Must be this flu I'm fighting.
The email address may appear hidden due to using
Mail's Smart Address feature but is not hidden when
viewing the long message headers for a received or
sent message.
Yes I know, but turning that off doesn't get rid of the Full Name, it just puts both the full name and the full address on there. And, even though I've deleted all Full Names in the problem accounts Mail still automatically puts the old Full Name in the email even though it's been deleted. Changing the name rather than deleting it doesn't help either, it still puts the original name in.
With one of these received messages sent to your AOL
email address for example but was received by and
deposited in the Inbox mailbox for your Spymac
account, at the menu bar go to View > Message and
select Long Headers.
Which email address is shown in the To: or Cc: field
- your AOL email address or your Spymac email address?
My AOL address sitting there the Spymac Inbox, otherwise I wouldn't know I had the problem. In fact, I just checked Spymac's Webmail and it's on their server too.
Kevin