Managing A Client's 100 Email Accounts

If there's a moderator lurking that knows of a better spot for this inquiry, by all means point away.

We're an ad agency in the very vertical market of Recruitment Communications.

We've developed an employment site that we host on our Multi-site account.

They have today requested a quote on what it would take to create 100 email accounts for their various employees and administrators on this employment site.

I initially think we tell them in the proposal that having their employees utilize webmail for their accounts would be least problematic (read: least cost support) for them. It's still going to present a bit of manual labor on our part creating the names, but not too daunting.

The client has no experience on staff that would be able to undertake the task as outlined above, so naturally we're concerned that their needs are indeed met in the best possible way.

One of our company's goals for all of our clients is to, as much as is possible, Under-promise/Over-Deliver. But as we're not specifically a "provider" in the typical sense of what they're asking, I am also thinking that it might be better for both the client and ourselves to examine whether this is a feasible undertaking.

If we were to undertake this 'project', and this is something you've experienced or read about, might you care to offer guidance on what guidelines we should assert/set-up? Web-mail versus Pop? Pricing structure? Support fees? Etceteras, etceteras.