Configure automatic outbound spam limits

Outbound limits help stop excessive mail from compromised mailboxes and websites. The sending block remains until an administrator removes it.

How it works

1. With Spam AutoShield and outbound limits enabled, cPFence checks Rspamd’s rate-limit events for excessive sending.
2. It adds detected senders to the outgoing-email block list. This block does not expire automatically.
3. Email and Slack alerts use your configured notification channels. Investigate the sender before removing its block.

WebUI method

1. Open Spam AutoShield → Settings and enable the master on the intended mail servers.
2. Use Edit rate limits to open System Settings.
3. Enable Outbound rate limits and set SMTP hourly limit and Website hourly limit.
4. Save, check the result, and configure email or Slack notifications if alerts are required.

The controls show saved settings for this server. Check the results after saving. Select the image for full size; use browser Back to return.

Adjust thresholds to your mail workload

Outbound limits are enabled by default when the Spam AutoShield master is active. Both packaged hourly limits are 200. The limit switch is effective only while Spam AutoShield is on. Review normal mailbox and website sending before choosing a threshold.

Filter the policy table to Block → Outgoing email to inspect blocked senders. Resolve the unwanted sending, then follow Unblock outgoing email.

If maintenance requires a temporary pause, turn Outbound rate limits off on the intended servers and save. Re-enable it afterwards. This switch does not remove existing sender blocks.

Command-line method

From a root terminal on the intended mail server, enable Spam AutoShield if needed:

cpfence --activate-spam-autoshield

Block a sender manually:

cpfence --add-spam-autoshield-out-email [email protected]

After fixing the cause, remove that same block:

cpfence --del-spam-autoshield-out-email [email protected]

Use the actual local sending account. These commands affect this mail server, not the WebUI’s server selection. Read the result and refresh its outgoing-email list. Change compromised passwords and check the account’s devices or website before restoring delivery.

Configuration-file alternative

The current settings are SPAM_AUTOSHIELD_LIMITS, MAX_SMTP_MSGS_PER_HOUR and MAX_WEB_MSGS_PER_HOUR in /etc/cpfcli/config.conf. Prefer the WebUI controls above. If editing the file as root, save a copy first and apply the change with:

cpfence --restart

This applies configured-off shutdowns and restarts configured-on protections, so plan the interruption and check the final output. Keep the Spam AutoShield master enabled for filtering; the outbound-limit switch controls this additional protection.