Introduction to POP and IMAP Protocols, Server Ports, Security and Authentication

On this page, you will find everything you need to know about the POP and IMAP protocols, server connection ports, security (encryption) of your email account connection, and authentication methods.

 

The POP Protocol

This protocol is designed for processing emails in "offline" mode: all emails are downloaded to the user's device by the email software and can be deleted from the server. The connection is then only necessary to check for new messages.

With the POP protocol, your email client will download messages at regular intervals and save them on the device currently in use. By default, messages are downloaded, saved on the device used, and deleted from the server after a defined period.

This operation allows quick access to data (for searching or sorting your messages).

 

It is possible to configure this type of POP account to:

- automatically delete from the server the emails that have already been viewed (downloaded to your device). You then do not have to worry about the disk space used on your hosting.

- keep a copy of messages on the server, either for a given period or indefinitely.
This configuration has the disadvantage of not providing direct visibility of the data stored on the hosting, but allows you to keep access to your recent emails from another device (mobile phone, laptop, tablet...).

 

POP Advantages
POP Disadvantages
  • Keeps a copy of messages on your device
  • Allows access to your messages offline (messages are stored on your machine)
  • Uses slightly less bandwidth and minimally uses server resources

 

  • By default, no copy on the server
     
  • Does not allow synchronisation of multiple devices
     
  • Does not allow synchronisation of folders such as "sent messages, spam, drafts, ..."
     
  • Backup management by the user: you must back up your computer or device

 

When you retrieve mail from a POP account, most email clients by default automatically delete messages from the server after a defined delay.

To retrieve your mail from another computer/device or if the mailbox is used by several people, you can configure your email clients so that a copy of each message is kept on the server until your other email clients have downloaded them. Simply adjust the retention period for messages on the server before deletion accordingly.

NB: It is also possible to adjust this setting to reduce the size of your hosting by shortening the storage period or by disabling mail storage on the server side.


Refer to the support of the email client you use for help configuring your software, particularly to learn how to modify email storage settings on a POP account, to delete or keep a copy of your messages on the server.

 

 

The IMAP Protocol

This protocol is recommended for use on multiple devices (synchronisation).

With this protocol, messages are not deleted when retrieved, but all changes made to your account (moving, marking, deleting) are also applied on the server side.

For these reasons, the IMAP protocol is very suitable for mobile use (successive connections from work, home or on the move...) as well as for managing a professional mailbox by several people, because changes made from one account are visible on all others.

It also benefits from backups made on the server since the data remains stored there. It is therefore possible to restore data in case of failure on your workstation.

 

IMAP Advantages
IMAP Disadvantages

 

  • The IMAP protocol allows simplified email management for mobility: management of folders and messages on the server
  • It allows management of folders such as “sent messages, drafts, spam, …”
  • It is easier to change email client (no messages to transfer, etc.) or to recover in case of loss or damage to the device
  • It can access multiple email accounts
  • Allows synchronisation of your messages on several email clients (or applications) at once
  • Disk space management: you need to manage your storage space on the mail server
  • Slightly slower than POP for searches and sorting
  • Folder management: certain email clients are slow to download and retrieve large folders
  • Uses slightly more bandwidth than POP on your internet connection: bi-directional exchanges for synchronisation

 

 

Ports

  • For IMAP:
    • Incoming server: 143 without security or 993 with SSL/TLS
    • Outgoing server (SMTP): 25 or 8025 (8025 not valid on SMTP SafeBrands) without security or 465 with SSL/TLS or 587 with STARTTLS
     
  • For POP:
    • Incoming server (POP3): 110 without security or 995 with SSL/TLS
    • Outgoing server (SMTP): 25 or 8025 (8025 not valid on SMTP SafeBrands) without security or 465 with SSL/TLS or 587 STARTTLS

 

TypeServer name / HostUsernamePortConnection securityAuthentication method
POPemail address995SSL/TLSNormal password
IMAPemail address993SSL/TLSNormal password
SMTPemail address587STARTTLSEncrypted password
SMTPemail address465SSL/TLSNormal password

 

The port 465 was implemented for email clients that did not support encrypted passwords. On port 465, it does not matter whether the password is encrypted or not, the session is encrypted, so it does not matter if the password is not.

On port 587, the password itself is encrypted and so it is the correct option to choose without connection security.