Subject not being replaced by VBA Macro - vba

Question

Okay so, I'm trying to edit this code I found that allows me to input variable information into a pop up box for emails. This is great and works flawlessly (although kinda slow), however I'm running into a weird issue trying to do the same thing with the subject line as well.
Using one template that I have set up, working template I get exactly what I'm looking for, it goes through all 4 of the variables INCLUDING the one on the subject line.
However, if I use a different template with the same variables, Not working template, it doesn't replace the subject line. The other two variables in the broken template pop up the dialog box - example
Can someone help fill me in on why it works on one template but not the other?
Full code:
Private WithEvents m_Inspectors As Outlook.Inspectors
Private WithEvents m_Inspector As Outlook.Inspector
Private Sub Application_Startup()
Set m_Inspectors = Application.Inspectors
End Sub
Private Sub m_Inspectors_NewInspector(ByVal Inspector As Outlook.Inspector)
If TypeOf Inspector.CurrentItem Is Outlook.MailItem Then
'Handle emails only
Set m_Inspector = Inspector
End If
End Sub
Private Sub m_Inspector_Activate()
Dim Item As MailItem
Dim Value As String
If TypeOf m_Inspector.CurrentItem Is MailItem Then
Set mail = m_Inspector.CurrentItem
'Identify the message subject
If mail.Subject = "FMAudit Legacy Install [custbusiness]" Or mail.Subject = "FMAudit Install [custbusiness]" Then
'Check message format
If mail.BodyFormat = OlBodyFormat.olFormatPlain Then
'Replace [date] with the entered value
If InStr(mail.Body, "[custname]") > 0 Then
Value = InputBox("Enter the customer name")
If Value <> "" Then
mail.Body = Replace(mail.Body, "[custname]", Value)
End If
End If
'Replace [percent] with the entered value
If InStr(mail.Body, "[custbusiness]") > 0 Then
Value = InputBox("Enter business name")
If Value <> "" Then
mail.Body = Replace(mail.Body, "[custbusiness]", Value)
End If
End If
'Replace [percent] with the entered value
If InStr(mail.Body, "[custhost]") > 0 Then
Value = InputBox("Enter host name")
If Value <> "" Then
mail.Body = Replace(mail.Body, "[custhost]", Value)
End If
End If
Else
'Replace [date] with the entered value
If InStr(mail.HTMLBody, "[custname]") > 0 Then
Value = InputBox("Enter the customer name")
If Value <> "" Then
mail.HTMLBody = Replace(mail.HTMLBody, "[custname]", Value)
End If
End If
'Replace [percent]; with the entered value
If InStr(mail.HTMLBody, "[custbusiness]") > 0 Then
Value = InputBox("Enter business name")
If Value <> "" Then
mail.HTMLBody = Replace(mail.HTMLBody, "[custbusiness]", Value)
End If
End If
'Replace [percent]; with the entered value
If InStr(mail.HTMLBody, "[custhost]") > 0 Then
Value = InputBox("Enter host name")
If Value <> "" Then
mail.HTMLBody = Replace(mail.HTMLBody, "[custhost]", Value)
'Replace [percent] with the entered value
If InStr(mail.Subject, "[custbusiness]") > 0 Then
Value = InputBox("Enter business name subject")
If Value <> "" Then
mail.Subject = Replace(mail.Subject, "[custbusiness]", Value)
End If
End If
End If
End If
End If
End If
Set mail = Nothing
End If
End Sub

Answer 1

Your code could be simplified a lot by creating a separate method which just does the replacements:
Option Explicit
Private WithEvents m_Inspectors As Outlook.Inspectors
Private WithEvents m_Inspector As Outlook.Inspector
Private Sub Application_Startup()
Set m_Inspectors = Application.Inspectors
End Sub
Private Sub m_Inspectors_NewInspector(ByVal Inspector As Outlook.Inspector)
If TypeOf Inspector.CurrentItem Is Outlook.MailItem Then
Set m_Inspector = Inspector 'Handle emails only
End If
End Sub
Private Sub m_Inspector_Activate()
Dim mail As MailItem
If TypeOf m_Inspector.CurrentItem Is MailItem Then
Set mail = m_Inspector.CurrentItem
'Check the message subject
If mail.Subject = "FMAudit Legacy Install [custbusiness]" Or _
mail.Subject = "FMAudit Install [custbusiness]" Then
ReplaceTags mail, "[custname]", "Enter the customer name"
ReplaceTags mail, "[custbusiness]", "Enter business name"
ReplaceTags mail, "[custhost]", "Enter host name"
End If 'matched subject line
End If 'is a mail item
End Sub
'replace tag `sTag` with user-supplied value in `mail` body and subject
Sub ReplaceTags(mail As MailItem, sTag As String, sPrompt As String)
Dim v, oBody As Object
'Check message format and get the body object
If mail.BodyFormat = OlBodyFormat.olFormatPlain Then
Set oBody = mail.Body
Else
Set oBody = mail.HTMLBody
End If
If InStr(oBody, sTag) > 0 Then 'check Body Text
v = Trim(InputBox(sPrompt))
If Len(v) > 0 Then oBody = Replace(oBody, sTag, v)
End If
If InStr(mail.Subject, sTag) > 0 Then 'check Subject text
If Len(v) = 0 Then v = Trim(InputBox(sPrompt)) 'don't re-prompt if already have a value
If Len(v) > 0 Then mail.Subject = Replace(mail.Subject, sTag, v)
End If
End Sub