How to Fix Squirrelmail Error “ERROR: Could not complete request. Query: SELECT INBOX Reason Given: Unable to open this mailbox.” on EHCP

Squirrelmail show this error when I tried to login to webmail:

ERROR: Could not complete request.
Query: SELECT “INBOX”
Reason Given: Unable to open this mailbox.

To fix the problem, check email folder and make sure it has the subfolder: cur, new, tmp with appropriate permission.

# cd /home/vmail/domain.com/email_username/

# mkdir new

# mkdir cur

# mkdir tmp

# chown vmail.vmail *