Check if the following looks like a list that will work. There should be instances where one partner has more than one email address. I suspect this should be OK. In other words, create multiple reports and multiple emails for a partner that has more than one email address.
By adding, [Prefix] & " " & [Full Name (Exc Prefix)] AS Partner, I suspect you will have a name to associate with an Email address. This could be included in the Body of the Email, e.g. "Dear " & rs![Partner] & ":"
Code:
SELECT DISTINCT [Prefix] & " " & [Full Name (Exc Prefix)] AS Partner, Missions.[E-mail address], Missions.Code
FROM [Non-Cheque Payments] INNER JOIN Missions ON [Non-Cheque Payments].Code = Missions.Code
WHERE ([Non-Cheque Payments].Code NOT IN ('CONEX', 'UNALL', 'PAYPA', 'FLOAT', 'WEC'))
ORDER BY [Prefix] & " " & [Full Name (Exc Prefix)];