I agree on the limit warnings. I've asked for that as well.

I'd add the following...

- Ability to add our own SMTP email relay settings, so that system emails could come from our address, instead of a voipwelcome.com address.
- Reseller definable email address field for usage notification alerts (default is blank). Along with a check box to notify to reseller, or not (default is checked).
- Separate limit threshold per account for notifications. For example, you might set the hard limit at 5000 minutes, but you could set the warning for 3000, 4000, whatever you like.
- More meaningful notification message (for outbound calls only) when hard limit is reached, rather than just a busy signal. Something like, "call limit exceeded, please contact your telephone service provider immediately."