Hi there !
I tried to use regular expression with your contact search engine but it doesn't seem to work. Example of request "student grade3 -exStudent".
In my case, it concerns particularly the exclusion symbol '-' which is very usefull as teacher to keep student contact even if they leave the course. The problem is I often need to select just the one category, the ones who are in the course and sometimes, just the ones who leaved the course years ago.
Thanks for your work !
This feature will definitely make me leave my actual "free" webmail