Sometimes, it happens that when you send emails, the recipient receive the same email many times in period of intervals. It is because of exim database got corrupted and also you receive following error in exim_mainlog.
Berkeley DB error: /var/spool/exim/db/retry: unexpected file type or format
Apply following solution to fix this issue.
Stop exim service using following command
[email protected][#] /etc/init.d/exim stop
[email protected][#] service exim stop
then go to /var/spool/exim/db/ and remove all the files. Make sure to take the backup of /db folder if in case if there is another problem arise.
Start Exim service.
[email protected][#] /etc/init.d/exim start
[email protected][#] service exim start
After starting exim service, It will rebuild exim database.
That’s all you are done..