Dear all, I don't know if this is the right place to speak about it, but I had this problem and found the solution : When trying to install perlsieve-0.4.9 on a server to connect to Cyrus (on another webserver) I have the following problem... IMAP::Sieve [ Login incorrect while connecting to bwsvrmail ]: NO "Authentication Error" Capability=LOGIN PLAIN And in Cyrus logs : Dec 15 03:30:47 server cyrus/sieve[30555]: badlogin: sourceserver[172.16.1.227] PLAIN error base64 decoding string BUT I FOUND THE SOLUTION, it was a bug in the usr/local/share/perl/5.10.0/IMAP/Sieve.pm file : If you get this problem, just replace : Old: $encode=encode_base64($userpass); New: $encode=encode_base64($userpass, ''); Denis ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html