Type Mismatch VBA cant be found - vba

Question

I have Finally got some working code but Im getting a "type mismatch" error once the Module2 function finishes and I have no idea why.
If I step through it, it steps through "End function" on module2 then I get a Type Mismatch, but it does send the email. Any help would be great
This VBA code is in 3 parts.
1 Sub
Sub Workbook_open()
Call Module1.GetData
End Sub
2 Module 1
Public EmailAddress As String
Public CompanyNumber As String
Public Name As String
Public GroupComp As String
Function GetData()
Dim LastRow As String
Dim rng As Range
LastRow = Cells(Rows.Count, "K").End(xlUp).Row
For Each rng In Range("K2:K" + LastRow)
If Not rng.Value = vbNullString Then
Select Case rng.Value
Case 1
Case Is = "True"
Let EmailAddress = ActiveCell.Offset(0, -5).Value
Let CompanyNumber = ActiveCell.Offset(0, -9).Value
Let Name = ActiveCell.Offset(0, -8).Value
Let GroupComp = ActiveCell.Offset(0, -7).Value
Call Module2.Email(EmailAddress, CompanyNumber, Name, GroupsComp)
Case 2
Case Is = "False"
End Select
End If
Next
End Function
3 Module 2
Function Email()
'MsgBox (EmailAddress)
Set objMessage = CreateObject("CDO.Message")
objMessage.Subject = "Stuffl " & (GroupComp)
objMessage.From = "Department Name(Department#Email.com)"
objMessage.Cc = "Department Name(Department#Email.com)"
objMessage.To = (EmailAddress)
MsgBox (EmailAddress)
objMessage.TextBody = "TEST"
objMessage.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2
objMessage.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "x.x.x.x"
objMessage.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25
objMessage.Configuration.Fields.Update
objMessage.Send
End Function

Answer 1

Change the Function Email() into
Function Email(emailaddress As String, companynumber As String, name As String, groupscomp As String)
You are not actually calling the Mail function , that's the problem i think

Answer 2

"i dont understand why I had to specify the variables again in the mail"
Whenever you pass values to a Sub or Function, you have to define that Sub or Function such that it is expecting to have values passed to it. So this won't work:
Sub Foo()
Dim i as Integer
i = 5
Call Bar(i)
End Sub
Sub Bar()
i = i + 2
End Sub
Because Bar() isn't expecting to have anything passed to it. This will work:
Sub Foo()
Dim i as Integer
i = 5
Call Bar(i)
End Sub
Sub Bar(i as Integer)
i = i + 2
End Sub
Because you have now told Bar to expect an integer to be passed to it.
Hope that helped.