1. Table

Here’s a table of the email server ports.

Ports Protocal Security Authentication Description
25 SMTP None AUTH Outgoing Messages
587 SMTP None or TLS STARTTLS Outgoing Messages
465 SMTP SSL SSL Outgoing Messages
143 IMAP None or TLS AUTH or STARTTLS Incoming Messages
993 IMAP SSL SSL Incoming Messages
110 POP3 None AUTH Incoming Messages
995 POP3 SSL SSL Incoming Messages
  • SMTP - The Simple Mail Transfer Protocol (SMTP) is for electronic mail transmission. User-level email clients typically use SMTP only for sending messages to a mail server for relaying.
  • IMAP - The Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection.
  • POP3 - The Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server.

2. What is the difference between POP3 and IMAP?

There are two possibilities for retrieving emails:

IMAP: Emails are synchronized between your computer and the email server. Furthermore, you can create your own folders on the server in order to sort or move your messages. These will then be available to you worldwide and on multiple devices.

POP3: Emails are “retrieved” from your computer and deleted by the server in the default setting. Due to this, you no longer have access to these messages. There is also no possibility to create folders on the server and to use these synchronously with several devices.

In summary:

  • If you use your email account with several devices and you would like to use your own folders, we recommend using IMAP.
  • If you only use one device for email access, access through POP3 is normally sufficient.

References