White-listing recipients?

Hello,

our university mail system uses greylisting. Some people appreciate
the spam-filtering effect but I personally would like to receive all
emails without delays and without the danger of losing any incoming
message (due to different sending IPs, for example).

I am not familiar with any of the greylisting implementations. Is there
any support in any of the implementations that allow individual users
(i.e. recipients) to opt-out of the system?

I would appreciate any pointers and/or ideas. (Please note that I am
not the admin on that system but someone who would like to forward such
pointers to the admins. Our university mail system is based on
sendmail 8.13.7.)

Thanks, Andreas.