Good, but be prepared for a learning curve. If you are somewhat familiar with mail protocols, its not too bad. Works well, and you CAN'T beat the price.
Docs are sketchy on line, you can purchase them (How David Harris funds Merc and PMail) Included help files cover most all situations if you take the time to read them thru, and several newsgroups as well as a forum on this site.
All in all.......Very Good