imapbackup

It is easy to use backup software like Shoviv IMAP Backup to back up POP accounts because the messages are stored in the profile. IMAP accounts are created to utilize messages stored in remote folders of the IMAP server. Beginning from Thunderbird 3.0, offline folders are turned on by default through Tools Account Settings> Account_name, Synchronization and Storage > "Keep messages from this particular account to this machine". An offline folder contains copies of all messages stored in the associated online folder. Offline folders are saved in mbox files, exactly as mail folders in POP accounts and Local Folders.