Disable an account in Apple Mail?

I have an email account under a domain that has been decommissioned. The domain still has an MX record, but its been disabled at the mail server. When someone tries to use the email address, they get a "550 Domain has been disabled" response back.

I cannot figure out how to disable the account. I've tried right clicking and "Take Offline", but that does not seem to help. Apple Mail still prompts me incessantly for a username and password. In addition, Apple Mail will no longer exit properly. It wants to throw a dialog for a password before it exits (that eventually requires a Force Quit).

I don't want to delete the account because I may need to refer to emails in the account.

How do I disable the account in Apple Mail?

(The operating system is OS X 10.8.5 (fully patched). Mail Version 6.6 (1510)).

Solution 1:

There are few ways to do this.

My Preferred way is::

Move all mails and folders you want to keep to "On My Mac" location.

Then in Mail app open Preferences--Accounts.

Uncheck the "Enable this Account"

It is now deactivated, but you still have the copies of the emails in your "On my Mac" location.

Sorry, the instructions are for 10.9.5.

As you will see the account is still there but grayed out, thus you can reactivate at any time.