Learn Java Mail Online   

The Technologies used: 

JavaMail 
is a Java API used to send and receive emails through standard mail protocols such as SMTP, POP3, 
and IMAP. It is built into the Java EE platform but is also available as an optional package 
for use in Java SE applications.

Spring JavaMail API
The Spring Framework provides a simplified and efficient way to integrate 
email functionality using  Spring JavaMailSender interface and related classes. 
This allows developers to easily configure mail servers and send or receive emails within Spring-based
applications.

Email Protocols:

SMTP (Simple Mail Transfer Protocol): A protocol used to send or deliver email messages.

POP3 (Post Office Protocol): A protocol used by email clients to retrieve emails from a mail server.

IMAP (Internet Message Access Protocol): A more advanced protocol that allows access to 
emails stored on the server without downloading them.

MIME (Multipurpose Internet Mail Extensions): Defines the format and content type of email
 messages, enabling the sending of multimedia content such as text, images, and attachments.