Commonly used mail servers support ports and encryption methods measured

Currently all ports must be logged in to send mail

Smtp.gmail.comg each port test situation

1. Does not support 25 port encryption or non-encrypted sending methods
2. 465 port support, need to encrypt and send with SSL method
3. Port 587 is supported and needs to be encrypted and sent with TLS method

smtp.office365.com

1. Only support 25 port TLS method encrypted transmission
2. Support port 587, TLS method encrypted transmission;

smtp.163.com

1. Support 25 port unencrypted and TLS method encrypted sending
2. Support 465 and 587 port SSL encrypted transmission
3. Port 994 is supported, it needs to be encrypted and sent with SSL method

smtp.qq.com

1. Support 25 port unencrypted and TLS method encrypted sending
2. 465 port support, need to encrypt and send with SSL method
3. Port 587 is supported and needs to be encrypted and sent with TLS method