$ sudo apt-get remove libytnef0 

Uninstall libytnef0 including dependent package

If you would like to remove libytnef0 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libytnef0 

Use Purging libytnef0

If you use with purge options to libytnef0 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libytnef0 

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 libytnef0 

See Also,