I try and try to send faxes from my email but it won't work.

Possible Answers:

1. You are not using the email account you signed up with to send the faxes. Your Internet fax provider knows the fax is from you by looking at the FROM on the incoming fax. If it's not from the email account you signed up with then you won't be able to send the fax. Usually they will send you a message saying "You must have an account on this service to send a fax"
2. You forgot to put a 1 in front of the US bound fox. If you forget the US country code then the fax provider likely sent the fax or tried to send it to an International phone number.
3. You forgot to hit send and receive. Not likely but given how many folks forget to plug stuff in and wonder why it does not work it is worth mentioning.