[Esd-l] Making procmail play "nice"

[Kenneth Porter]

--On Saturday, September 27, 2003 2:17 PM -0600 Brett Glass 
<brett at lariat.org> wrote:

> In other words, the mod_perl approach: Trade memory for some CPU
> cycles.

Sounds right. Of course, memory is relatively cheap (incrementally) 
compared to CPU, and a mail server tends to be memory-bound.

BTW, I've been thinking about giving a penalty to any "large" message, 
which would also help to discourage HTML. I'm basing the idea on the Linux 
traffic control (tc) packet queuing system. The idea would be to have the 
MTA dump messages above some size threshold into a slow queue (maybe 
several with service times scaled by message size). Small text-only 
messages would get immediate delivery. HTML would stall 15-30 minutes, 
justified because of the extra resources needed to scan it for malicious 
content and spam. Large attachments might be held for an hour. Queues would 
have quotas and a full queue would cause new messages for that queue to be 
rejected. Any but the text-only queue would get emptied at a constant, slow 
rate.

Has anyone tried implementing something like this? Would this be feasible 
with sendmail, or would a custom MTA be needed?