cPanel® & WHM® for MailChannels Outbound Filtering

Overview

MailChannels Outbound Filtering protects your cPanel mail servers from being blacklisted by identifying and blocking spam and abusive traffic originating within your network. The plugin integrates directly into the cPanel & WHM interface, allowing administrators to seamlessly manage outbound email security and automate DNS record provisioning.

Key Benefits

• Centralized Tracking: Gain full access to the MailChannels Host Console, providing real-time centralized log summary data for all outbound communications.

• Flexible Protection: Secure all hosted domains globally, or explicitly define specific include/exclude parameters.

• Threat Response Automation: Receive compromised account and abusive activity alerts. Standard and higher tier subscriptions include webhook notifications to trigger automated threat mitigation responses.

• Remediation Tooling: Custom automated false positive/negative remediation links are directly injected into Non-Delivery Report (NDR) bounce responses.

Prerequisites & Requirements

Before initiating the installation, verify your server ecosystem fulfills the following baselines:

Installation & Maintenance

1. New Plugin Installation

To provision the MailChannels plugin v3 on a cPanel instance, log into your server terminal via SSH as a superuser (root) and execute the deployment sequence:

wget https://s3.amazonaws.com/mailchannels-reseller/plugins/mailchannels-cpanel-v3-installer \
&& bash mailchannels-cpanel-v3-installer

2. Upgrading from v2

⚠️ Important Upgrade Notice

If the legacy v2 cPanel plugin is currently active on the system, it must be removed. The v3 installer script will automatically look for and prompt you to remove the v2 plugin. If you decline the prompt, the installer will safely terminate, and you must manually drop the v2 footprint before attempting to run the v3 script again.

3. Uninstalling the Plugin

To safely strip the plugin, execute the core uninstallation script as the root user:

/usr/local/mailchannels/bin/uninstall.sh

Available Flags

• --purge : Completely wipes all associated log footprints (/var/log/mailchannels) and active config records (/etc/mailchannels) from disk.

  • Note: If you run the script without the --purge flag, these directories persist and config elements located at /etc/mailchannels/* must be manually deleted to remove them fully.

  • Note: If MailChannels Outbound is active when this flag is thrown, the routine automatically disables outbound filtering without showing an interactive prompt.

Navigation & Initial Setup

1. Log into your cPanel / WHM Admin Dashboard.

2. Utilize the search box at the top of the left navigation pane and search for "MailChannels".
   

3. Click the MailChannels menu item, to launch the interactive management environment.

API Key Synchronization

ℹ️ Notice

This section is strictly required for customers utilizing MailChannels Inbound processing models. Outbound-only configurations can bypass this view and move on to the Outbound Configuration.

1. Inside the MailChannels user interface, click Configuration on the left navigation bar.

2. Click the API section header to expand the entry panel.

3. Retrieve your unique API token directly from the MailChannels Host Console API Keys Page.

4. Input your token into the field provided and click Update.
   

Outbound Configuration Reference

To customize outbound validation routines, expand the Outbound dropdown panel inside the main Configuration view.

ℹ️ Status Check Block

New installations display an alert indicator stating: "Your outbound account is not protected. You can manage your SMTP Passwords in the host console." This error resolves immediately following credential verification and activation check.

Configuration Fields & Toggles

MailChannels Account ID

Enter your SMTP Username This alphanumeric signature is located at the top right of your Host Console Dashboard.

SMTP Password

Provide your SMTP password, generated via your host console profile interface under Settings > Account > SMTP Passwords.

Enable Outbound Filtering

• Checkbox: Checking this will enable MailChannels Outbound Filtering when you update the settings

• Function: Once verified credentials are saved, checking this activates the rule engines, rerouting the local Exim MTA mail queue transport layer through the MailChannels platform.

Automatically update domain SPF records

• Checkbox: Automatically update domain SPF records when MailChannels Outbound Filtering is enabled or disabled, or when new accounts are added

• Function: Instructs the local nameserver backend to dynamically adjust TXT zone declarations on host accounts to authorize MailChannels relays.

DNS Lookup Limiter

• Checkbox: Do not provision domain if adding MailChannels SPF records will exceed the ten DNS Lookup limit

• Function: Protection toggle ensuring automated SPF generation actions will not break the rigid RFC maximum limit of 10 structural domain lookups.

Enable DKIM signing

• Checkbox: Enable DKIM signing

• Function: Enables cryptographic domain key email signing for your outbound mail stream to prevent tampering and improve deliverability.

Enable MailMan Headers

• Checkbox: Enable MailMan Headers. You must also have 'enable MailChannels Outbound Filtering when you update the settings' checked. Any changes made via Exim Configuration Manager will cause these changes to be overwritten. Please enable this setting again in that case

• Function: Special headers layer that preserves mailing list management tracking properties across dynamic smart-host configurations.

Domain Lockdown Automation

• Checkbox: Automatically add Domain Lockdown TXT record when MailChannels Outbound Filtering is enabled or disabled, or when new accounts are added

• Function: Automates TXT security tracking parameters to seal verified domains against outside identity spoofing attacks.

Known Operational Issues

Our engineering teams currently monitor and isolate the following core technical limitations across the cPanel framework:

SPF Automation Constraints

1. Sub-domain Limitations: While the automation script cleanly processes primary entries across standard WHM profiles, Addon Domains, and Parked Domains, SPF records for native cPanel sub-domains are NOT automatically updated at this time. These entries require manual zone generation.

2. Scale Limits (Large Node Timeout): High-density cPanel configurations exceeding 1,000+ localized active domains experience timeout drops during mass batch updates. The automated mechanism may exhaust system limits and stop execution before successfully processing all accounts on the node.