About
A Mail User Agent (MUA) is the technical term from a email client application.
User agent in Mail User Agent (MUA) means that it's a user application (known as user agent on the web)
A MUA can:
- read and write in the mailbox
List
Gui
- outlook
- Gmx
- Thunderbird (windows, mac, linux)
Command line
- sendmail - the reference command that you should find on all linux distribution.
echo -e "Subject:Hello World \n\n This is my first mail \n" | sendmail [email protected]
- mutt
- elm
Library
- Java: https://github.com/HubSpot/NioSmtpClient - netty based
Management
Which client has created the mail
In the header field of an email, search for the value User-Agent
Example:
User-Agent: Heirloom mailx 12.5 7/5/10
Where does the name and email of the author come from?
The email internet address is composed of:
- for the email address:
- the user login
- for the user name: the user name or the user comment
On Linux:
- the user login may be set in the $USER variable
- the email address may be set in the $MAIL variable
- the user login and comment (user name) are in the /etc/passwd file.