$ sudo apt-get remove procmail 

Uninstall procmail including dependent package

If you would like to remove procmail and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove procmail 

Use Purging procmail

If you use with purge options to procmail package all the configuration and dependent packages will be removed.

$ sudo apt-get purge procmail 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove procmail 

See Also,