RFC 5322 is an internet standard that describes the syntax and format of electronic email messages. It was published in 2008 and replaced earlier standards like RFC 2822 and RFC 822. RFC 5322 defines how email messages should be structured to be correctly interpreted by email clients and servers. Some important aspects of RFC 5322 include:

• Addresses: RFC 5322 sets the syntax for formatting email addresses, including sender addresses (From), recipient addresses (To), copies (Cc), and blind copies (Bcc).

• Headers: RFC 5322 describes how various headers of email messages, such as subject (Subject) and date (Date), should be created and formatted.

• Message body: It establishes rules for the body of an email message, including text content and attachments.

• Character encoding: RFC 5322 includes recommendations for character encoding, important for messages in different languages and character sets.

• Text format: It defines rules for formatting text within email messages, including indentation, alignment, and paragraphs.

RFC 5322 is a crucial standard that ensures the interoperability of email systems, allowing email messages to be readable and correctly processed by all clients and servers. It is a key document for the development and implementation of email applications and infrastructure.