Problem Description
When it comes to sending and receiving email, two key concepts need to be distinguished: MAIL FROM and FROM. Although both concepts relate to the sender of the message, they play very different roles in the message delivery process.
Detailed Introduction
MAIL FROM are instructions used in SMTP(Simple Mail Transfer Protocol) to specify the sender of a message. When a mail server is ready to send a message, it uses the MAIL FROM directive to indicate the source address of the message to the receiving mail server. This address is often used for reverse path verification to confirm the source of the message and to notify the sender when the message cannot be delivered.
The FROM field appears in the actual content of the message and tells the recipient who the message looks like it was sent by. This field is at the head of the message and is one of the first lines of information that the recipient sees. The FROM field can contain one or more email addresses or even a display name. However, the contents of the FROM field can be easily modified, so it does not guarantee the true origin of the message.
Difference Summary
MAIL FROM is a technical instruction for mail delivery in the SMTP protocol. It is used for communication between mail servers and identifies the sender address of a mail.
The FROM field is part of the email header and is displayed in the body for the recipient's reference. It indicates the sender information of the email, but its authenticity needs to be verified by other methods.
Understanding the difference between these two concepts helps to better identify the true source of email and avoid spam and phishing attacks. When dealing with important or sensitive emails, it is a common security practice to confirm that the MAIL FROM address is consistent with the sender information displayed in the FROM field.