How do filters throttle suspicious senders?

Throttling suspicious senders limits potential damage:

Throttling mechanisms:

Connection limits: Fewer simultaneous SMTP sessions. Message limits: Fewer messages per connection. Time delays: Forced pauses between messages. Volume caps: Daily or hourly send limits.

Triggers for throttling:

Unknown or new sender. Reputation concerns. Unusual volume patterns. Content red flags.

Progressive throttling:

Initial delivery at reduced rate. Behavior monitored during throttle period. Good behavior: limits ease. Bad behavior: limits tighten or block.

Sender experience:

Increased deferrals. Slower delivery times. 4xx responses asking to slow down.

Throttling is probationary access. Prove yourself trustworthy, and limits will ease.