+1. I’m a paid up user of Email Alchemy, it’s one of those sub-50USD apps that pay for themselves with one job / client, especially where Outlook is ancient and inexplicably still working.

(and I paid for it after paying two consultants to help me, so although it is a niche market, it could be bigger than you think)

Emailchemy looks like a pretty useful tool. I'll take a look!