What is E-mail authentication?

All technologies used for e-mail messages in the e-mail transport system with verifiable information is called e-mail authentication.  It is an important element in current times to control the menace of spam e-mail by scamsters. E-mail authentication is a coarse-grained authentication, usually at administrative management domain and implies no sort of authorization. The purpose of e-mail authentication is to verify the identity of the sender who participated in transferring a message, as they can modify the message. The results of such validation can then be used in delivery decisions, which are beyond the scope of e-mail authentication, and are quite different in nature from content filtering.