Multiple Groups but eliminate dups

[Lynn]

If a person has included someone in GroupA for email
distribution. The person is also in GroupB, but most are
not. Most times the emails are sent just to one group or
the other. But if we send the same email to both Groups
A & B, then that one person would get the email twice.
Is there a way within Outlook to prevent duplicates when
combining multiple groups?
Thx