Java mail

We have used many emails, QQ, 163, Netease, etc.

1、 SMTP protocol should be followed when sending e-mail, and POP3 protocol should be followed when receiving e-mail

2、 Process of sending e-mail

Suppose you use QQ mail

Write e-mail -- > click "send" -- > QQ e-mail server receives e-mail (if QQ is used to send e-mail to Netease e-mail, next, QQ e-mail server forwards it to Netease e-mail server)

3、 Send mail using SMTP

After being familiar with SMTP protocol, you can send e-mail without any software.

For example, we use QQ email to send email to our friends

Step 1: connect to QQ's mail server:

QQ's mail server is: SMTP qq. COM port is 25. You can see this by clicking "help" in the mailbox.

At the command line, enter telnet SMTP qq. Com 25, the effect is as follows, successfully connected to the server

Step 2: say hello to the server

Continue to enter: Ehlo Zhangsan in the command window. The effect is as follows:

Step 3: log in to the mail server

Continue to enter: auth login. The effect is as follows:

Step 4: enter user name and password

For example, your email address is 11111111@qq.com Then your username is 11111111

Enter user name enter

Enter the password and press enter to see whether the returned message is successful

Note: base64encoder code is required for user name and password here. The coded code is as follows. Put the user name and password in and run to get the transcoded string

It's best to use the program to change your user name and password in advance, then put it in Notepad and paste it into the command window, because too slow input will lead to loss of connection.

Step 5: tell the server, sender and recipient

Sender: the email you just logged in to, namely: 11111111@qq.com

To: is your friend's email, such as 222@qq.com

Continue to enter the command: mail from:< 11111111@qq.com >Enter

Continue to enter the command: RCPT TO:< 222@qq.com >Enter

Step 6: start writing email

You can start writing mail only after you have successfully logged in in the previous step

　1. Enter data on the command line and enter

2. Enter email content

For example:

　　from:< 111111111@qq.com > 　　to:< 222@qq.com Subject: Holiday Notice

The company is scheduled to have a three-day holiday on XXX. enter

Note: here (> to:< 222@qq.comsubject : Holiday Notice) can not be written, that is, only the following words are written. Give it a try and you'll see the difference.

　　3. Tell the server that the mail is finished and can be sent

Enter "." Then enter

Done.