I have a lot of clients that do email blast. Some of there mailing list have a large amount of invalid address so we get a lot of bounce backs and fills up our mail que.

Is there any software that would clean these mailing list?
I've tried a fer programs out there but you can really clean a mailing list from a home computer. most free email providers block you like yahoo aol msn etc.
and running list from home will get you blocked from alot of service providers.

Does anyone have any idea how to handle clients with these types of mailing list?