Increase Exchange 2010 Mailbox Recipient Size Limit, Exchange Shell Command

If you need to email more than 25 people at once, which is the default setting, it stops you.

Go to start, programs, exchange 2010, and exchange management shell (as admin).

 

Type “Set-Mailbox john.doe@domain.com -RecipientLimits 50” and hit enter. Make sure you change the email address there to the proper mailbox and change the “50” to the number you want to set the limit to.