sendmail causing high load

[Jasper Bal]

Hi all,

My isp blocks traffic on port 25. So i decided to experiment on adding a 
listening port for sendmail. I added port 53, because this is never 
blocked. I added the following line in sendmail.cf: OOPort=53. I killed 
-1 sendmail. And then all my connections timed out. Ping gives a 80% 
loss. Are there that many wild dns requests? The box doesn't run his own 
dns-server, nor is it registered as one. I'm running OpenBSD 3.7 on this 
one. Any thoughts?

Kind regards,
Jasper