What process is generating dead.letter? I'm using linux: Distributor ID: Ubuntu Description: Ubuntu 18.04.6 LTS Release: 18.04 Codename: bionic I noticed a few weeks ago that there is a file in my home directory: `dead.letter`. The file is updating at the first second of every minute with the same number of log line. I have been searching for the process that cause this over a week for now and still can't find it. I've tried < \+ `auditctl`, killing and uninstalling docker, verifying multiple location where cron jobs may be. Disabling the cron process. \+ mail sendmail and mailx commands are not recognized. I can't find the process that causes this. Please help.

Found the problem: We use nfs mounts in our organization. We also use AWS.

We created a new instance from an ec2 instance I was working on. The template instance had a cron job, that kept running on the new instance, and writing data to the shared directory.