Win2k3, Exchange2003 sp1

The system is working fine for a year now. Last week a user complaint that
he sends some mails in a specific domain (abc.com) and they never received
them. I checked the queue and the domain was there on retry with 8 mails.

We find out later that abc.com had problems with their mail but they fix it.
I still have the domain on my queue so i double-click, find messages and
delete them with no-ndr. The amount of messages on the domain abc.com is 0
but it still appears on the queue. It's been over a day and the domain is
still there on the list.

Does it suppose to take so long ? Is this normal ? am i missing something ?

Thank you!!!