Can't dotlock /root/sent

I have a CRON script that emails daily using mutt.

This script has begun to fail, and I now get an email from cron stating:

Can't dotlock /root/sent.

Couldn't lock /root/sent

Could not send the message.

The wierd thing is that I get this email from cron fine, but mutt can't send email. The cron job is run by root, so I don't think this is a permissions issue.

Can anyone shed some light on this?

From serverfault Josiah

• Is there a /root/sent file/directory/link/other existent ? Is there an other process which take the lock for a while ? Check with lsof -n | grep /root/sent. The rights are good on this file ?

  Josiah : There was a /root/sent.lock file, I deleted this file and it worked!
  From Dom