Mailserver Configuration in WHM

WHM provides you with a full list of options to customize the built-in Dovecot mail server to suit your email needs.

You can reach the Mailserver Configuration page under the Service Configuration section of WHM. This guide is intended for Hostwinds Cloud VPS clients who have a cPanel license and access to WHM or any Hostwinds Dedicated Server clients with a cPanel license with access to WHM.

Mailserver Configuration

• Protocols Enabled: Specifies what mail protocols Dovecot listens on.
• IPv6 Enabled: Specifies whether to have Dovecot listen for IPv6 address requests.
• Allow Plaintext Authentication: Specifies whether remote clients are required to use encrypted messages or if plaintext messages are allowed.
• SSL Cipher List: Specifies the SSL ciphers Dovecot should use.
• SSL Protocols: Specifies the SSL protocols Dovecot should use.
• Maximum Number of Mail Processes: Specifies the maximum number of mail processes that can be run simultaneously.
• Process Memory Limit for Mail: Specifies the maximum memory usage for the mail process in MB.
• Maximum IMAP Connections Per IP Address: Specifies the maximum number of IMAP connections allowed from a single IP address at one time.
• The interval between IMAP IDLE "OK Still here" messages: Specifies the amount of time between IMAP IDLE "OK Still here" messages in minutes.
• Maximum POP3 Connections per IP Address: Specifies the maximum number of POP3 connections allowed from a single IP address at one time.
• Several Spare Authentication Processes: Specifies the number of spare authentication processes that should be kept running to listen for new connections.
• Maximum Number of Authentication Processes: Specifies the maximum number of authentication processes that may be running simultaneously.
• Process Memory Limit for Authentication: Specifies the maximum memory usage allowed for the mail login processes in MB.
• Size of Authentication Cache: Specifies the cache the master authentication process uses to cache validated logins in MB.
• Time to Cache Successful Logins: Specifies the amount of time failed logins are stored in the authentication cache in seconds.
• Use New Authentication Process for Each Connection: Specifies whether or not to use a new login process for each mail connection.
• Process Memory Limit: config: Specifies the maximum amount of memory in MB for Dovecot's 'config' service.
• Idle Check Interval: Specifies the amount of time in seconds between updates to idle SMTP connections.
• Include Trash in Quota: Specifies whether or not to include the size of the trash towards an account's usage quota.
• Compress Messages: Specifies whether recently created and delivered messages should be compressed.
• Compression Level: Specifies the level of compression used when compression is enabled.
• Auto Expunge Trash: Specifies whether the Trash and Deleted Messages folders have their contents automatically removed based on the expiration time.
• Trash Expire Time: Specifies the time in days to keep messages in the Trash or Deleted Messages folders before being removed if Auto Expunge Trash is enabled.
• MDBOX Rotation Size: Specifies the maximum size in MB an MDBOX mailbox file can grow before the system rotates.
• MDBOX Rotation Interval: Specifies the maximum amount of time in days or weeks an MDBOX mailbox file can exist before the system rotates it.
• Disk Quota Delivery Failure Response: Specifies whether mail will be rejected permanently or deferred temporarily when the mailbox disk quota prevents delivery.
• Minimum Available LMTP Processes: Specifies the minimum number of processes to be reserved to accept more client connections.
• LMTP Process Limit: Specifies the maximum number of LMTP processes that can be run simultaneously.
• LMTP User Concurrency Limit: Specifies the maximum number of LMTP deliveries per user at any one time.