I’ve been using Evolution mail client in Ubuntu for quite sometime now,without much hassle. But recently, I performed a hard restart on my Laptop and when I tried accessing Evolution, it could not retrieve mails from one of the local folders used to store my official mails from M$ Exchange.

The status bar would show “Error generating mail list”, and when I checked the debug reports, it attributed an error stating: “Database image is malformed”.

After looking up at launchpad’s  bug report , it was hinted there that the problems in the database folder file ‘folder.db’ would result in this error.
I followed the following steps to correct it:

• Run this command in the terminal to verify the status of the folder.db files 

cd ~/.evolution/mail ; for i in `find . -name folders.db`; do echo "Rebuilding Table $i"; sqlite3 $i "pragma integrity_check;"; done

• As I did not have sqlite3 installed, I installed it from Universe repositories, 

 sudo apt-get install sqlite3

• After installing sqlite3, I ran the first command again. This time, the command rebuilt the missing folder.db files, and also showed erroneous folder.db file. 

Rebuilding Table ./vfolder/folders.db
ok
Rebuilding Table ./pop/raghavendra@xyz.com@mail.abc.com/folders.db
ok
Rebuilding Table ./local/folders.db
*** in database main ***
On page 4 at right child: 2nd reference to page 218
Page 420 is never used
Error: database disk image is malformed

• After you find out the erroneous file, delete it from its location, and close all evolution processes including evolution-dataserver and evolution-alarm notifier. 
• Now execute the first command again, and verify if there are any more errors by running

sqlite3 ~/.evolution/mail/local/folders.db "pragma integrity_check;"

•  After these steps, I started Evolution to find the error resolved.