[Dovecot] help: The current command did not succeed. The mail server responded: Invalid mask.

[Ivo Rütsche]

on your mozilla client: go to "Edit" / "Mail & Newsgroups Account 
Settings" / [your account] / "Server Settings" / "Advanced..." / "IMAP" 
/ "Other Users"

make sure your text box is empty (default is "~")


bye ivo