Typically within 5 minutes the fax would have been delivered. If there are problems, or the destination fax is busy, the system usually retries up to 5 times with various intervals. In any case you would get a notification on failed delivery as well as successful delivery if you chose to have that.

You can send as many as you like, a 10.000 fax broadcast typically lasts a little over an hour to send to all the recipients, after which another try is done in case the destination fax was busy. We do recommend to have 3 retries in total, with the first fax sent in the evening, 2nd try the next morning, and 3rd try the next afternoon. That way you make sure the fax is not bounced because the receiving end switches off the machine, or ran out of paper.