Create mailing with spreadsheet data

I am using Office 2007. I have a spreadsheet in which each row contains
manager information (name, email) and corresponding employee information
(name, email). Each employee is a unique row however some managers may appear
in more than one row as they may have more than one employee reporting to
them. I would like to create a mail merge of some type using this data where
each manager would receive an email containing a generic message into which
the names of their corresponding employees would be inserted. Is there any
way to automate this?