Mail Throttles

/jabali-admin/mail/throttles. Outbound mail rate-limit policy enforced by Bulwark and Stalwart (M47 Wave 3).

Why throttle outbound

A compromised mailbox or runaway PHP script can generate thousands of messages per minute. Without per-sender caps, the panel’s outbound IP rapidly accumulates reputation damage that takes weeks to recover. Throttles bound the worst case before it leaves the network.

Configurable limits

Scope	Units	Default
Per mailbox	messages / minute	30
Per mailbox	messages / hour	500
Per mailbox	recipients / message	100
Per domain	messages / minute	300
Per domain	messages / hour	5000
Per IP	messages / minute	1000

Override per-mailbox or per-domain by adding a row in the Overrides tab.

Enforcement

• Bulwark intercepts SMTP submission on :587 / :465, checks the per-sender counter against the limit, and returns 421 4.7.0 throttled, try later when exceeded.
• Stalwart maintains the per-IP counter and applies the policy on outbound MTA delivery.
• CrowdSec observes throttle hits and escalates a sender that hits the limit repeatedly within a short window to a temporary suspension.

Excluded paths

• System-generated mail (recovery emails, notifications from the panel itself) is exempt.
• Mailing-list expansion (if implemented in a future release) will count once per outbound recipient batch, not once per list member.

Suspending a sender

When CrowdSec escalates a sender, the panel:

1. Disables the mailbox login (Stalwart returns 535 5.7.8 on AUTH).
2. Fires a mail_throttle_suspended notification (see Notifications).
3. Records the suspension in the audit log.

The admin clears the suspension from the mailbox edit page once the cause is understood.

Monitoring

The page renders the past 24 hours of throttle hits as a per-sender heatmap. Click a sender to drill into the per-minute history.