Sender: The sender of the email is equivalent to from's secretary, conveying the message for from.

A valid letter header must include the "From:" line

A valid letter header may include a "Sender:" line

If the letter includes "From:" also includes "Sender:", then "Sender:" is the sender

If the letter includes "From:" but does not include "Sender:", then the first character in "From:" This address is the sender

If the letter does not include "From:", then the letter must not be signed by DomainKey (including the case where there is "Sender:" but no "From:") < /p>

E-mail is a communication method that uses electronic means to exchange information. It is the most widely used service on the Internet. Through the network's email system, users can send emails at a very low price (no matter where they are sent, they only need to pay the network fee) and in a very fast way (it can be sent to any designated destination in the world within a few seconds). Connect with Internet users anywhere in the world.