dave demo.ps1

#Contents of MyFile.csv
#
#To,Subject,Body
#firstguy@fake.tld,subject1,<p>body</p>
#secondguy@fake.tld,subject2,<i>italic body</i>

$csvContents = Import-Csv MyFile.csv
$defaultEmailParams = @{
    'SmtpServer' = 'EmailRelay'
    'BodyAsHtml' = $true
    'From' = '"Mr. Spammer" <spam@fake.tld>' 
}

foreach ( $row in $csvContents ) {
    $specificEmailParams = @{
        'To' = $row.To
        'Subject' = $row.Subject
        'Body' = $row.Body
    }

    Send-MailMessage @defaultEmailParams @specificEmailParams
}