Milter-greylist

> Current limits for greylist:
>  plimit 20180
> 20180:  /usr/local/bin/milter-greylist
>    resource              current         maximum
>   time(seconds)         unlimited       unlimited
>   file(blocks)          unlimited       unlimited
>   data(kbytes)          unlimited       unlimited
>   stack(kbytes)         8192            unlimited
>   coredump(blocks)      unlimited       unlimited
>   nofiles(descriptors)  2048            2048
>   vmemory(kbytes)       unlimited       unlimited
> 
 
Could you try to limit the number of available file descriptors to 254 as a workaround?
Please use the vanilla code of milter-greylist-2.0.2 to test with,
of course if you have time and interested in the test.