GFI FaxMaker Online client supports both protocols HTTPS or SMTP to send faxes. The support for HTTPS has been integrated with the latest available GFI FaxMaker Online build (starting with build 05 June 2014.)
The difference between HTTPS and SMTP is the method through which the fax request is submitted by the FaxMaker Online client. With HTTPS protocol the GFI FaxMaker Online client makes secure HTTPS API calls using port 443, while with SMTP protocol the client submits fax requests as emails using port 25 to send faxes.
When the HTTPS submission method is used, the GFI Faxmaker Online client will not generate notification reports. For the SMTP submission method, the sender will receive a fax transmission report, if notifications are configured as described in User Notifications.