Want To sent and receive email to specific Domain block all other for incoming and outgoing

SYSTEM INFORMATION
OS type and version Ubantu 20.4
Webmin version 1.990

This person @Kapil_Jangra is too busy to take the time to enter an appropriate title or fill out the body of the message and he thinks we are here to do his bidding, his slaves and servants who need from him not even a please or thank you.

We should.impose a penalty on such people: make them donate to Virtualmin if they wish to seek help from the community.