Odd behaviour on Convertto-HTML and Send-MailMessage

I have the Following script, and it outputs to a file just fine, but when it comes to emailing it, it says that the message body i get the following error:

Send-MailMessage : Cannot validate argument on parameter 'Body'. The argument is null or empty. Supply an argument that is not null or empty and then try the command again.

here's my script 

#Setting Date of One Week Back
$week = (Get-Date).AddDays(-7)
$today = (Get-Date).ToString()

$style = @'
<style>
body {
	font: normal 11px auto "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif;
	color: #4f6b72;
	background: #E6EAE9;
}

a {
	color: #c75f3e;
}

#mytable {
	width: 700px;
	padding: 0;
	margin: 0;
}

caption {
	padding: 0 0 5px 0;
	width: 700px;	 
	font: italic 11px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif;
	text-align: right;
}

th {
	font: bold 11px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif;
	color: #4f6b72;
	border-right: 1px solid #C1DAD7;
	border-bottom: 1px solid #C1DAD7;
	border-top: 1px solid #C1DAD7;
	letter-spacing: 2px;
	text-transform: uppercase;
	text-align: left;
	padding: 6px 6px 6px 12px;
	background: #CAE8EA url(images/bg_header.jpg) no-repeat;
}

th.nobg {
	border-top: 0;
	border-left: 0;
	border-right: 1px solid #C1DAD7;
	background: none;
}

td {
	border-right: 1px solid #C1DAD7;
	border-bottom: 1px solid #C1DAD7;
	background: #fff;
	padding: 6px 6px 6px 12px;
	color: #4f6b72;
}


td.alt {
	background: #F5FAFA;
	color: #797268;
}

th.spec {
	border-left: 1px solid #C1DAD7;
	border-top: 0;
	background: #fff url(images/bullet1.gif) no-repeat;
	font: bold 10px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif;
}

th.specalt {
	border-left: 1px solid #C1DAD7;
	border-top: 0;
	background: #f5fafa url(images/bullet2.gif) no-repeat;
	font: bold 10px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif;
	color: #797268;
}</style>
'@


# Email Variables
$smtp = "smtp.domain.com"
$to = "group@domain.com"
$from = "System Reports<guido.oliveira@domain.com>"
$subject = "Recent Users and Groups Report"



# Import Module of Active Directory
Import-Module -Name ActiveDirectory

# Run Command 
$Users = Get-ADUser -Filter * -Properties * | `
	where { $_.whenCreated -ge $week } | Select-Object -Property @{ Name = 'Nome'; Expression = {$_.name} }, `
														@{ Name = "Login" ; Expression = { $_.SamAccountName } }, `
														@{ Name = "E-mail" ; Expression = { $_.mail }}, `
														@{ Name = "Departamento" ; Expression = { $_.Department } }, `
														@{ Name = "Unidade" ; Expression = { $_.Office } },  `
														@{ Name = "Endereco" ; Expression = { $_.StreetAddress } }, `
														@{ Name = "Empresa" ; Expression = { $_.Company } }, `
														@{ Name = "Cidade" ; Expression = { $_.City } }, `
														@{ Name = "Equipe" ; Expression = { $_.Description } },   `
														@{ Name= "Criacao" ; Expression = { $_.WhenCreated }} `
                                        	| ConvertTo-html -PreContent "<H2>Usuarios criados nesta Semana.</H2>" -Fragment
#  Group
$group = Get-ADgroup -Filter * -Properties * | `
	where { $_.whenCreated -ge $week } | Select-Object -Property @{ Name = 'Nome'; Expression = {$_.name} }, `
													@{ Name= "Criacao" ; Expression = { $_.WhenCreated }}, `
													@{ Name = 'Nome'; Expression = {$_.name} }, `
													@{ Name= "Descricao" ; Expression = { $_.Description }} `
                                       	 	| ConvertTo-html -PreContent "<H2>Grupos criados nesta Semana.</H2>" -Fragment 

#  Folder
$folders = Get-ChildItem -Path "\\netshoes.local\shares\work\Zona Compartilhada" -Attributes "Directory" | `
	where { $_.CreationTime -ge $week } | Select-Object -Property @{ Name = 'Nome'; Expression = {$_.name} }, `
														@{ Name= "Criacao" ; Expression = { $_.CreationTime }}, `
														@{ Name = 'Caminho'; Expression = {$_.FullName} }, `
														@{ Name = 'Proprietario'; Expression = {$_.Owner} }  `
                                        	| ConvertTo-html -PreContent "<H2>Diretorios criados nesta Semana Na Zona Compartilhada.</H2>" -Fragment 
$btitle = "<H2>Periodo de criacao de $week a $today.</H2>" | ConvertTo-Html -Fragment
$title = "<H1>Recent Users and Groups Report</H1>" | ConvertTo-Html -Fragment
$message = ConvertTo-Html -Head $style -Body "$btitle $Users $group $folders" -Title "$title" -As Table


$message

Send-MailMessage -SmtpServer $smtp -To $to -Body $message -From $from -Subject $subject -BodyAsHtml

What am i missing