Why doesMail maddengly keep attempting to send with an old deleted account?

Question

Every now and then, Mail "decides" to use an old account to send from.
I've been back into preferences and cancelled the account.
No such account exists at my server. It was only registered in Mail.
It is unable to send these emails using the cancelled account.
At some point it "reverts" to trying to send it with my primary account successfully. Sometimes it doesn't revert and I have to send the emai from another machine.
Where could this glich be hiding?

Answer 1

I found that "old" email account in the Outgoing Mail
Server pop up menu and removed it as you suggested.
That in effect solved that problem, however when
sending mail from the corrected account
Just a clarification. You didn't "correct" that account. You just removed an undesired server from the list of outgoing (SMTP) servers that Mail keeps independently of any particular account.
Any outgoing server created via the "Server Settings..." button in the Account Information pane for any account automatically gets added to that list and becomes available to all accounts.
Any modifications made to the list of outgoing servers from any account are independent of the particular account you used to make the changes. If you remove a server off that list from a particular account, the server also becomes unavailable to the other accounts.
Despite appearing as part of the Account Information pane, the list of outgoing servers itself is not tied to any particular account in any way. Only the choice of a particular server from that list is part of the account settings.
I now get this message from time to time when
sending to a "group" in my Address Book.
This message could not be delivered and will remain
in your Outbox until it can be delivered.
The server "mail.optusnet.com.au" rejected the
address "83001885". Changing the group name into a
number!!
If I send to individuals from this group it works OK
I find it hard to believe that this could be related in any way to the problem that originated this thread. If the solution proposed by Ernie doesn't work, I'd suggest starting a new thread with this new problem so that other users not interested in the original question can benefit from the discussion, unless you believe both problems are indeed related.
BTW, if the solution suggested by Ernie doesn't work I have no idea what the problem could be. The fact that sending to individuals in that group works while sending to the group as a whole doesn't, suggests that when sending to the group Mail chooses a different address for some of the recipients, so you should examine the addresses giving special attention to any addresses that you don't use when sending to individuals.
iMac G5 17" (iSight)   Mac OS X (10.4.4)