IMAP vs POP3 vs SMTP
POP3, IMAP and SMTP are the three most commonly used Internet email configurations. Each protocol provides a specific function and this article will describe in detail how they work. Read on to learn which configuration will work best for you.
Post Office Protocol version 3 (POP3) is an mail protocol used to retrieve mail from a remote server to a local email client. POP3 copies the mail from the remote server into the local mail client. Optionally, mail is deleted after it is downloaded from the server. This saves space on the server.
If you frequently access your mail account from multiple devices/locations, POP3 may not be the best option for you since it is not able to synchronize your mailbox across multiple devices. However, POP3 is a very simple mail protocol making it less prone to errors and allows for a much easier implementation.
Ports used for POP3:
- Port 110 – Default POP3 port.
- Port 995 – POP3 port used for SSL/TLS.
IMAP is an mail protocol used to access a mailbox on a remote server from a local email client. IMAP can be more complex, but provide more convenience for syncing across multiple devices.
Ports used for IMAP:
- Port 143 – Default IMAP port. Also used for TLS.
- Port 993 – IMAP port used for SSL
Simple Mail Transfer Protocol (SMTP) is used to send mail.
Ports used for SMTP:
- Port 25 – This is the default SMTP port. A lot of local ISPs (Telus, Shaw) have been blocking port 25 due to Spam, so you may not be able to send mail if you configure SMTP to use port 25.
- Port 587 – As an alternative to port 25, you can configure your mail client to use port 587 to send mail. This is the port we recommend for Navigator email users to avoid any issues.
- Port 2525 – Navigator’s email server also supports 2525, which is another alternative to port 25.
These are the 3 main email configurations.