Missing events because of insufficient group notice allowance is very annoying.
UPDATE to this OP: The problem is two-fold.
1) LL cuts off group notices at a certain number. This is bad for customers, for groups trying to hold events, and ultimately for Linden Lab (which relies on those groups for income).
2) Group Notices are not being consistently sent out by email. This failure caused me to miss two of my favorite events of the year. The notices were sent out, but never appeared in my email. I have an email filter specially designed to never stop an LL email, and I do receive most group notices.
The two events which did not reach me were held by Raglan Shire: Golden Bow Archery Contest and Stabby Stabby event. There's no way to know how many notices are not reaching me. Initial guess: SL's email system isn't functioning properly.
end of update