One Email to Rule them All - email

Question

I have this script that takes a CSV and pings servers and tells me their status and then sends me an email on ones that are unreachable. The Below script works great, but the only thing I would like to change is instead of receiving multiple e-mails per unreachable server I get one email containing all of the servers that are unreachable after it has finished pinging.
I know that part of the problem is that I have the email line inside the IF, Else. So I was thinking about creating a variable and doing a new line, but I need help to see what that looks like.
Any help or advice would be appreciated. I've tried looking on Microsoft's script page and googling as well.
$hostnamestxt = "C:\Scripts\printers.csv"
$servers = Import-Csv "$hostnamestxt"
$date = get-date
foreach($server in $servers) {
$serverName = $server.Name
$serverAddress = $server.IP
if (test-Connection -ComputerName $serverAddress -Count 2 -Quiet)
{
write-host "$serverName is ONLINE" -foregroundcolor black -backgroundcolor green
}
else
{
write-host "$serverName, $serverAddress is OFFLINE/UNREACHABLE" -foregroundcolor black -backgroundcolor red
Send-MailMessage -Body "$serverName, $serverAddress is OFFLINE/UNREACHABLE at $date" -From "emailaddress" -Subject "$serverName, $serverAddress is OFFLINE/UNREACHABLE at $date" -To "emailaddress" -SmtpServer "emailaddress"
}
}

Answer 1

You could create an empty array and then add the server name for devices that are offline, then you would send the email. Something like this would probably do what you are looking for:
$servers = Import-Csv -Path "C:\Scripts\printers.csv"
$date = get-date
$Array = #()
foreach ($server in $servers) {
$serverName = $server.Name
$serverAddress = $server.IP
if (test-Connection -ComputerName $serverAddress -Count 2 -Quiet)
{
write-host "$serverName is ONLINE" -foregroundcolor black -backgroundcolor green
}
else
{
write-host "$serverName, $serverAddress is OFFLINE/UNREACHABLE" -foregroundcolor black -backgroundcolor red
$Array += $serverName
}
}
Send-MailMessage -Body "The Following Devices are Offline $Date: $Array" -From "emailaddress" -Subject "Servers Offline $date" -To "emailaddress" -SmtpServer "emailaddress"