'Mass-mailing' With ASP?

I just took over maintaining an ASP codebase for sending out
newsletters by mail, as well as basic subscriber maintenance.

Thing is working ok today, with ~200 subscribers, but there are plans
on selling this 'solution' to clients with substantially higher
demands; at least in the low 1000's..

Would you consider asp suitable for this purpose? Would be a
definitive plus not having to use other technology, but i'm concerned
about timeouts and whatnot while sending out such a batch of mail.

Guess it could be made workable with tons and tons of logging, and
maybe generating a client redirect every X mails, to restart/keep the
script going?

Or is it perhaps possible to fork off a new thread and do this as a
real background task? I'm not too knowledgeable on ASP, and neither
was the guy who wrote this system in the first place, unfortunately.