Which ports do I need to open on my firewall to send SMS messages using the Clickatell service?

Answer

An SMS can be sent with GFI FaxMaker using either the Web2SMS or the Email2SMS interface. For the Web2SMS interface, the SMS will be sent using the HTTP(S) API. Port 80 and / or 443 must be open for this purpose. For the Email2SMS, the SMS will be sent using the SMTP API. Port 25 must be open for this purpose.