Rated 4 out of 5 stars

Hi gaby_hy
When replying or forwarding an e-mail with no subject, SmartTemplate doesn't come into action. The default Thunderbird reply or forwarding headers (ugh!) are used instead. I tried to put the %subject% field in reserved brackets—"{" and "}"—but that didn't make any difference.
Hope this helps,
Alex FX

This review is for a previous version of the add-on (0.4.3). 

In ver0.4.3, exception occurs when no subject.
I will fix bug in next version.
And brackets working only %to...% and %cc...%.