Hi,
Is there a way for courier to detect/prevent mail floods? Say maybe restrict up to a maximum number of connections from any IP.
That's already the case. You may set an upper limit on the number of connections from the same IP address, or from the same /24.
Another question, does dupfilter work "good enough" or is there a need for a better dupfilter implementation? If so, is there already one out there for download?
Well, it's definitely good enough as far as speed goes. You can't get any faster than it already is. The only question is whether its dupe detection logic is good enough.
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