MailItems are one of the more commonly automated items in the Outlook VBA object model. Here's how we can create them using several different methods.

Follow the links above to learn more about the MailItem's methods, properties and events.

Create MailItem in default local folder

MailItems can be created in the default Inbox folder using the Outlook.CreateItem Method.

Function CreateMailitem() As Outlook.AppointmentItem
  Set CreateMailitem = Outlook.CreateItem(olMailItem)
End Function

Create Mailitem in non-default local folder that holds mail items

MailItems may be created in any folder that can hold them. Pass a MAPIFolder Object to this function and it uses the Folder.Items.Add Method to create a new message and pass it back to the calling procedure for further manipulation.

Function CreateMailItemAltFolder(fldr As Outlook.MAPIFolder) As Outlook.MailItem
  If fldr.DefaultItemType = olMailItem Then
    Set CreateMailItemAltFolder = fldr.Items.Add(olMailItem)
  End If
End Function

Create MailItem in shared default folder

You may create MailItems in a shared folder to which you have access. You pass in either a resolved Recipient object or the name of a user whose shared Inbox folder you have access to and want to create a message for.

Function CreateSharedDefaultMailItem(recip As Variant) As Outlook.MailItem

Dim olNS As Outlook.NameSpace
Dim fldr As Outlook.MAPIFolder
Dim tempRecip As Outlook.recipient

  Select Case TypeName(recip)
    Case "Recipient"
      ' Recipient object already created
      Set fldr = olNS.GetSharedDefaultFolder(recip, olFolderInbox)

    Case "String"
      ' create Recipient object
      Set olNS = GetNS(GetOutlookApp)
      Set tempRecip = olNS.CreateRecipient(recip)

      Set fldr = olNS.GetSharedDefaultFolder(tempRecip, olFolderInbox)

  End Select

  Set CreateSharedDefaultMailItem = fldr.Items.Add(olMailItem)

End Function
Function GetNS(ByRef app As Outlook.Application) As Outlook.NameSpace
  Set GetNS = app.GetNamespace("MAPI")
End Function
Function GetOutlookApp() As Outlook.Application
' returns reference to native Application object
  Set GetOutlookApp = Outlook.Application
End Function

If a Recipient object is passed to the function, the new MailItem is created directly. If only a name is passed, a temporary Recipient object is created using the Outlook.NameSpace.CreateRecipient Method.