Send confirmation message if command ran with Invoke-Expression completes successfully - powershell

Question

I'm writing a PowerShell script to add / remove people from a distribution group. I want to send a message if the action was successful and another if it failed. This is part of the script:
foreach ($x in Get-Content $pathfile\inputfile.txt) {
$USER = $x.Split(',')[0]
$ACTION = $x.Split(',')[1]
$COMMAND = (Write-Output "$ACTION-DistributionGroupMember -Identity 'Group Name' -Member $USER")
if ($ACTION -ieq "remove") {
$COMMAND = $COMMAND + ' -Confirm:$false'
Invoke-Expression $COMMAND
}
else {
Invoke-Expression $COMMAND
}
}
inputfile.txt, for the sake of information is:
jdoe#example.com,Add
jsmith#example.com,Remove
I've tried using $? and $lasExitCode but neither of those worked as expected as they only consider the output of "Invoke-Expression" and that is always successful.
What I am expecting is:
foreach ($x in Get-Content $pathfile\inputfile.txt) {
$USER = $x.Split(',')[0]
$ACTION = $x.Split(',')[1]
$COMMAND = (Write-Output "$ACTION-DistributionGroupMember -Identity 'Group Name' -Member $USER")
if ($ACTION -ieq "remove") {
$COMMAND = $COMMAND + ' -Confirm:$false'
Invoke-Expression $COMMAND
#if $COMMAND successful: Write-Output "$ACTION on $USER succeeded."
#if $COMMAND unsuccessful: Write-Output "$ACTION on $USER failed."
}
else {
Invoke-Expression $COMMAND
#if $COMMAND successful: Write-Output "$ACTION on $USER succeeded."
#if $COMMAND unsuccessful: Write-Output "$ACTION on $USER failed."
}
}

Answer 1

$? won't work because even if the command fails, Invoke-Expression was invoked successfully.
Use the & call operator to invoke the call directly instead, and $? will work. For the conditional parameter argument, use splatting!
foreach ($x in Get-Content $pathfile\inputfile.txt) {
$user,$action,$null = $x.Split(',')
# construct command name
$command = "$ACTION-DistributionGroupMember"
# organize the parameter arguments in a hashtable for splatting later
$paramArgs = #{
Identity = 'Group Name'
Member = $USER
}
# conditionally add the `-Confirm` parameter
if ($ACTION -ieq "remove") {
$paramArgs['Confirm'] = $false
}
# invoke the command with the call operator
& $command #paramArgs
if($?){
# command invocation suceeded
}
else {
# command invocation failed
}
}