You may get the following error message:
Send-MailMessage : Cannot convert 'System.Collections.ArrayList' to the type 'System.String' required by parameter 'Body'. Specified method is not supported.
This error message is really explicit: The body of the mail must be a string and you are giving an array as input.
Unfortunately, you cannot use the ToString method.
$Body = $MyArray.ToString()
In this case, all you will get is a mail with only the System.Collections.ArrayList expression.
In order to convert the body to a string, you must use the
$Body = $MyArray | Out-String