Fax sent email subject

This is the subject of the email that is sent when a fax is sent. Available variables are:

• <TMPL_VAR NAME=NUMBER> The called number
• <TMPL_VAR NAME=DONE> Boolean, takes the value of 1 if the fax has been sent successfully
• <TMPL_VAR NAME=REQUEUED> Boolean, takes the value of 1 when the fax is requeued after a failure, ie there are re-tries still left
• <TMPL_VAR NAME=FAILED> Boolean, takes the value of 1 when the fax attempts have exhausted their re-tries, ie the fax is considered failed
• <TMPL_VAR NAME=ERROR> A string containing error information