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For cPanel & WHM version 11.52

(Home >> Service Configuration >> Mailserver Configuration)

Overview

The following options appear when you access WHM's Mailserver Configuration interface while you run the Courier mail server. 

Note:

Select your mailserver in WHM's Mailserver Selection interface (Home >> Service Configuration >> Mailserver Selection).

Mailserver Configuration options

Choose the desired settings for each option in the table below, and then click Save.

  • To return to the default values for all configuration options, click Use Default Values.
  • To undo your changes, click Reset. 

Configuration optionDescription
Protocols Enabled

Select the checkboxes to enable the desired protocols.

Warning:

  • If you attempt to save the configuration without a protocol, WHM disables the Mailserver Configuration feature.
  • To reenable the Mailserver Configuration feature, select a mail server in WHM's Mailserver Selection interface (Home >> Service Configuration >> Mailserver Selection).

Note:

cPanel’s Webmail feature requires that you enable the IMAP protocol.

IPv6 Enabled

Select the checkboxes to enable IPv6 address connection requests on the desired protocols.

Important:

You must select the desired protocols' Protocols Enabled checkboxes before you select those protocols' IPv6 Enabled checkboxes.

Maximum IMAP Connections (Total)The maximum total number of IMAP connections that are possible at one time.
Maximum IMAP Connections Per IP Address

The maximum number of simultaneous IMAP connections that one IP address's mail server may make.

Note:

The system only applies this setting if you enabled an IMAP protocol. 

Maximum TLS/SSL IMAP Connections Per IP Address

The maximum number of secure IMAP over SSL (IMAPS) connections that one IP address 's mail server may make.

Note:

The system only applies this setting if you enabled an IMAP protocol. 

IMAP TLS/SSL Protocol

The TLS or SSL protocols that a secure IMAPS connection can use.

Note:

The system only applies this setting if you enabled an IMAP protocol. 

For more information, read the TLS/SSL section below.

IMAP TLS/SSL Cipher List

The list of ciphers, in standard format, that the mail server can use to connect to your server with the IMAP protocol.

Note:

The system only applies this setting if you enabled an IMAP protocol. 

For more information, read OpenSSL's ciphers documentation.

IMAP Empty Trash

The number of days that a message remains in a trash folder before the system deletes it.

Note:

The system only applies this setting if you enabled an IMAP protocol. 

Maximum POP3 Connections (Total)

The maximum number of simultaneous POP3 connections.

Note:

The system only applies this setting if you enabled a POP3 protocol. 

Maximum POP3 Connections per IP Address

The maximum number of simultaneous POP3 connections that one IP address's mail server may make.

Note:

The system only applies this setting if you enabled a POP3 protocol. 

Maximum TLS/SSL POP3 Connections Per IP Address

The maximum number of simultaneous POP3 over SSL (POP3S) connections that one IP address 's mail server may make.

Note:

The system only applies this setting if you enabled a POP3 protocol. 

POP3 TLS/SSL Protocol

The TLS or SSL protocols that a secure POP3S connection can use.

Note:

The system only applies this setting if you enabled a POP3 protocol. 

For more information, read the TLS/SSL section below.

POP3 TLS/SSL Cipher List

The list of ciphers, in standard format, that the mail server can use to connect to your server with the POP3 protocol.

Note:

The system only applies this setting if you enabled a POP3 protocol. 

For more information, read OpenSSL's ciphers documentation.

Number of Authentication Daemons

The maximum number of authentication daemons that can run simultaneously. Consider the needs of your mail server before you enter a value that is not the default value.

Notes:

  • A high number of authentication daemons can cause your server to run slowly. Authentication daemons can consume large amounts of system resources.
  • A low number of authentication daemons can cause your server to run slowly due to a lack of daemons to authenticate each session.

TLS/SSL

Transport Layer Security (TLS) and Secure Sockets Layer (SSL) are two cryptographic protocols that computers use for secure communication over the Internet. Email and web browsers often use these protocols. Essentially, they perform the same tasks.

Both of these protocols initiate a “handshake,” during which your server and the user’s computer agree on specific conditions. These conditions include a set of public and private keys that the two computers use to encrypt and decrypt messages that they send during the secure session.

As a web server, your server identifies itself when it receives a request from a user. SSL allows you to generate and sign your own certificates, which you can use to authenticate servers. However, we do not recommend self-generated, self-signed certificates, because they are generally not secure. Because self-generated, self-signed certificates do not use a third-party verification system, any server could claim to be your server.. To remedy this, register with a certificate authority (CA). The CA independently verifies that visitors interact directly with the correct server.