LetterContent.SalutationType (Word)

Returns or sets the type of salutation for a letter created by the Letter Wizard. Possible return values are wdSalutationBusiness - Business salutation, wdSalutationFormal - Format salutation, wdSalutationInformal - Informal salutation, wdSalutationOther - Custom salutation.

Set myContent = New LetterContent 
myContent.SalutationType = wdSalutationBusiness 
Documents.Add.RunLetterWizard _ 
 LetterContent:=myContent, WizardMode:=True