Celoxis provides a unique way for users to reply via email and have their replies filed in the appropriate place; be it task communication, task updates or forum topic replies.

When user A sends an email from task to user B, the application stores the email in it's database, changes the Reply-To email header to something like: celoxis+<control-information>@company.com and sends it to user B. When user B replies to that email, the email lands up for the celoxis's email inbox (not user A's inbox because the Reply-To header was changed). Celoxis periodically polls its inbox and when it finds the reply emails there, processes it by first looking at the control-information. The control information has the task ID and other related information. After the replied email is filed for that task, celoxis sends the email to user A (again with the Reply-To header changed with new control information).

In case you have chosen not to use the plussed style addressing, the control information is added to the subject of the email.