'everyone' add book entry not working

[Guest_imported]

Have a problem with emails to the everyone group entry not actually going to everyone!

Theres no pattern to it i can see. Only 1 exchange 5.5 sp3 server running on a 2 server network.

sp4 ok to install?

 

[Zelandakh]

Have you updated the users in the everyone group recently?

 

[siknightley]

no new users added... all original.