For example:
Currently if a user tries to send an e-mail to bob@smith.com, but they accidentally type bob@smith.cm, the mail server will dutifully try to connect to smith.cm for 7-10 days before returning an undeliverable error mail to the sender.
How do you change the timeout time on this setting. I'd like to make it about a day and a half or so.

Oh, and we're running 3.1.3

Thanks