Import-CSV - Check Mail-Contact fields to see if changed and if so Set-Contact

TechGuy1815  Something like this:

if (!Test-Path $CSVFileName) 
{
    Write-Error "Cannot find $CSVFileName"
    exit(1)
}

foreach ($line in $csvfile) 
{
    $contact = Get-Contact -domaincontroller $dc -Identity $line.Name -ErrorAction SilentlyContinue
    if($contact)
    {
        # The Contact exists, check details
        if( 
            ($contact.Department -ne $line.Department) -or 
            ($contact.Title -ne $line.Title) -or 
        )
        {
            # update ALL of the contacts details if any detail is different
            Set-Contact ...
        }
    }
    else 
    {
        # new contact
        New-MailContact ...
        Set-Contact ...
    }
}

but if the script is not run very often, or if there are not too many users listed int he file, you could try:

if (!Test-Path $CSVFileName) 
{
    Write-Error "Cannot find $CSVFileName"
    exit(1)
}

foreach ($line in $csvfile) 
{
    $contact = Get-Contact -domaincontroller $dc -Identity $line.Name -ErrorAction SilentlyContinue
    if(!$contact)
    {
        # Contact does not exist, so create a new contact
        New-MailContact ...
    }

    # Always update the contact details cause the caontact exists now
    Set-Contact ...
}

In this second option you always update the contact details from the data in the file.

Definitely try this in a test environment first.