Mass email

I am one of the moderator’s of an ADULT group. Since it is an adult group, It’s necessary for ALL members to have their birth date in their profile… many ‘pending’ members forget to do this, and therefore, I cannot approve them. Is there a way to send a mass email to ALL the ‘pending’ members at once asking them to fill out their birthdates in their profiles? (sending 50 individual emails is a looonngg and tedious process!)

Even though I have not sent any emails, it tells me i have reached my limit for the hour to prevent abuse of the system. I was able to send them out before. These emails are for my students to let them now about my classes.