Add a Counter to the title of the Send-MailMessage - powershell

Question

I want to add a counter, so the number of tickets send will increase by 1 every time an email is sent. I had it working on another powershell script but on this one, seems that something is wrong. Maybe someone can give me a hand with this:
Edit: The counter displays always #1, after every email sent.
if ($Counter -eq $null){
$Counter = 1
}
$Email = "test"
$Internal = ""
$Subject = "Error #$Counter - Test - $(Get-Date -format dd/MM/yy)"
[array]$attachments = Get-ChildItem "path"
if ([array]$attachments -eq $null) {
}
else {
$Msg = #{
to = $Email
cc = $Internal
from = "someone"
Body = 'body'
subject = "$Subject"
smtpserver = "server"
BodyAsHtml = $True
Attachments = $attachments.fullname
}
Send-MailMessage #Msg
$Counter++
}

Answer 1

If you want the counter to always increase, you can store it in the registry or store it in a text file like so:
if(-not(Test-Path C:\PathTo\Counter.txt)){
1 > C:\PathTo\Counter.txt #create the file with a default counter
}
$TicketCounter = [int](Get-Content C:\PathTo\Counter.txt)
#restOfYourScriptHere
$TicketCounter++ #as needed to increment
#end of your Script
$TicketCounter > C:\PathTo\Counter.txt #saves the new counter value