You can also try SquirrelMail, I personally find round cube to be the best one. What are some of the problems you are having with roundcube?
Ok, can you give us a little more info on your setup? and this error happens when you try to login to roundcube or when?
Also can you post the mail log file it should be at /var/log/maillog
Sure. I followed this tutorial.
https://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassasin
Here is the output:
http://pastebin.com/Rn3ktV1H
This error does happen when I try to login to Roundcube. I tried logging in as root and as another username
from looking at your mail log, it doesn't seem like there is a problem. Check your /etc/hosts file and double check that this code is there
127.0.0.1 localhost
What Os are you running, nginx or apache?
The 127.0.0.1 localhost in the hosts file is there. I'm running apache. Thanks for all your help so far!
Sorry it took me a while to answer. Lets try this.
Execute each of this commands, it will delete all dovecot index files, and dovecot will re-create them when it notices they're missing.
cd /home
/etc/init.d/dovecot stop
rm -f */imap/*/*/Maildir/dovecot*
rm -f */imap/*/*/Maildir/.*/dovecot*
rm -f */Maildir/dovecot*
rm -f */Maildir/.*/dovecot*
/etc/init.d/dovecot restart
Are you running Ubuntu? What version? have you recently updated anything on the server?