Rkhunter - no mail on warning: new issue (Solved)

[galeforce]

This is a similar issue with the same software not mailing on warnings.
Rkhunter is performing fine and creating a log but the mail process is not working.
This is with Linux Mint Cinnamon 20.2.
For some reason postfix is not following through. warnings.

Settings checked and double checked and are same as Linux Mint Mate 20.2
Default file checked, postfix reconfigured and it appears to make the call to /bin/mail (etc)
Early error showed in initial setup for mail as no permission except for root which is where it's supposed to go.
Thinking Cinnamon may need more mail utility.
Any thoughts would be appreciated.

Thanks to Moen suggesting new topic on old thread

[galeforce]

Initially installing from the repository postfix picked up my provider, though local was specified.
Having run into this before it seemed a simple matter of using dpkg-reconfigure postfix to make it function local only, no provider.
Unfortunately this did not take and main.cf had to be edited and the sysctl after command run in order for it to work properly.
Comparing the main.cf to previous other systems main.cf there was a big difference between several lines in the main.cf even after placing the proper strings during the postfix reconfigure.
The "myDestination line was missing the local host name but also $myhostname,computer name, localhost.localdomain, localhost
Also "mynetworks =" was empty.
Once these were edited to match previous strings the mail worked fine.
In my opinion it may be better sometimes to install postfix offline for local setups to prevent the ISP from being picked up as the localhost.
Also the ucf file in /var/lib/ucf/cache maintained an improper local host which once edited did not solve the issue but may have helped.
Hope this helps someone.