I'm seting mailserver by reference http://www.howtoforge.com/virtual-u...courier-mysql-and-squirrelmail-debian-squeeze step by step. until step test SquirrelMail login with user with i'm create in step14. i'm found return error message in squirrelmail login Code: ERROR: ERROR: Connection dropped by IMAP server. and when check log of /var/log/mail.err Code: Jul 21 14:05:19 mailoffice imapd: [email]email@example.com[/email]: No such file or directory Jul 21 14:20:25 mailoffice imapd: [email]firstname.lastname@example.org[/email]: No such file or directory what directory It's mean? and how to fix this problem.