Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Invented by Ray Tomlinson, email first entered limited use in the 1960s and by the mid-1970s had taken the form now recognized as email. Email operates across computer networks, which today is primarily the Internet.
If you are sure that any emails contains material that is not
allowed in Islam, then it will not be allowed to process or forward
the same to others.
Thank you for your question. It is generally praiseworthy to be an approachable and kind person in normal circumstances. However, that is within the bounds of wisdom and chastity. It is not necessary to reply a typed salaam whether that be by email or other forms of instant messenger.
May you always be successful.