Select account for VBA script - vba

Question

I have written code to limit the number of addresses for the To, CC and BCC fields.
The only problem is the code affects all accounts and not a specific account which I select.
e.g: user1#xyz.com
user2#xyz.com
I want this code to work only for the "user1#xyz.com" account and not the "user2#xyz.com" account. But the code is running in the whole Outlook session. Is there any option to choose the account in the code?
Private Sub Application_ItemSend(ByVal Element As Object, Cancel As Boolean)
Dim aaa() As String
Dim bbb() As String
Dim ccc() As String
aaa = Split(Element.To, ";")
bbb = Split(Element.CC, ";")
ccc = Split(Element.BCC, ";")
If (UBound(aaa) + 1) + (UBound(bbb) + 1) + (UBound(ccc) + 1) > 10 Then
MsgBox ("You have added too many recipients! Please contact your Administrator."), vbExclamation, "Authorization required!"
Cancel = True
End If
End Sub

Answer 1

I've written a lot of VBA, but none for Outlook, so I'm guessing a bit here. How about inserting this before you Split anything:
If LCase(Environ("Username") & "#" & Environ("Userdnsdomain")) <> "user1#xyz.com" Then Exit Sub
?

Answer 2

You can find the applicable account like this
Private Sub Application_ItemSend(ByVal Element As Object, Cancel As Boolean)
Dim oAccount As account
For Each oAccount In Session.Accounts
If oAccount = "user1#xyz.com" Then
Dim aaa() As String
Dim bbb() As String
Dim ccc() As String
aaa = Split(Element.To, ";")
bbb = Split(Element.CC, ";")
ccc = Split(Element.BCC, ";")
If (UBound(aaa) + 1) + (UBound(bbb) + 1) + (UBound(ccc) + 1) > 1 Then
MsgBox ("You have added too many recipients! Please contact your Administrator."), vbExclamation, "Authorization required!"
Cancel = True
End If
End If
Next
ExitRoutine:
Set oAccount = Nothing
End Sub