MASS MAIL to CONTACTS in SELECTED ACCOUNTS

MASS MAIL to CONTACTS in SELECTED ACCOUNTS

I know most of us would like to email our clients with special offers.   As a result, the best avenue is to selected by ACCOUNTS (ex: type "customer) and then email to all CONTACTS in that account.  The problem I see is that you can't work off 2 databases (ACCOUNTS & CONTACTS).

Is it possible?

NOTE:  I have PROFESSIONAL version.