the email address of the receiver, the header and the message
Message Header
The Basic Header contains information about the source of the message. The Application Header contains information about the message type and the destination of the message. The contents of the trailer block include both user information (checksum, message authentication, proprietary authentication, and so on) and system information (delayed message, message reference, possible duplicate message, and so on).
HEADER – Address – subject – Attachment – Message – signature Line
Did you try Wireshark?
The HTTP protocol simply declares the entire length of the message in part of the header called "Content-length header field".
REQUEST HEADER
1. Who the message it to. 2. Who the message is from. 3. The message itself.
removes the Ethernet header and trailer
Let us now analyse the message header, body, and signature separately.
The parts of an email message are similar to a letter. They are a header (addressing the email with an introduction such as dear), the message body (content of the message), and the signatures (the closing of the letter with a send off such as "regards".
A RIP (Routing Information Protocol) message that advertises only one network consists of the RIP header and a single route entry. The RIP header is 4 bytes, and each route entry is typically 20 bytes. Therefore, the total size of a RIP message advertising one network is 4 bytes (header) + 20 bytes (route entry) = 24 bytes.