Is there any way that I could post reply from email?

I sincerely hope not! We get enough spam as it is.

These forums are not a ticket system, they’re forums and if you want to reply you need to log in and well, reply to a topic or raise a new topic. I hope that never changes.

It’s a great feature on a ticketing system but these community forums are not that.

Edit: That goes double if you are a theme, plugin author or support person. These forums aren’t your ticket system and please do not think they are.