Send-mailmessage and Get Content - Adding HTML to my password reset policy email

Hello guys. I am trying to update an old script we have had in our company. This script sends users an email when they are within 9 days of having to reset their passwords. The formatting is horrible and looks horrible. I want to take on the task of either learning how to attach a PDF document to the email sent to users that explains to them how to reset their passwords. Or make the building of the email HTML so i can format something nice. Can you help me get this accomplished please.  Here is the script. 

#Add the Quest PowerShell snapin 
Add-PsSnapIn Quest.ActiveRoles.ADManagement -ErrorAction SilentlyContinue 
Get-QADUser -SizeLimit 0 | Select-Object samAccountName,mail,PasswordStatus |  
Where-Object {$_.PasswordStatus -ne "Password never expires" -and $_.PasswordStatus -ne "Expired" -and $_.PasswordStatus -ne "User must change password at next logon." -and $_.mail -ne $null} |  
ForEach-Object { 
  $today = Get-Date 
  $logdate = Get-Date -format yyyyMMdd 
  $samaccountname = $_.samAccountName 
  $mail = $_.mail  
  $passwordstatus = $_.PasswordStatus 
  $passwordexpiry = $passwordstatus.Replace("Expires at: ","") 
  $passwordexpirydate = Get-Date $passwordexpiry 
  $daystoexpiry = ($passwordexpirydate - $today).Days 
  $smtpserver = "htc-001" 
   $emailFrom = "expiringpasswords@Contoso.com" 
  $body = "Please change your password to prevent loss of access to Systems" 
  $body += "This is important! Waiting to change your password will most likely result in getting locked out of important systems.
  			
			If you are unable to change your password, please contact the help desk at 410-295-8124 or send an email to Help@Contoso.com
  			ONLY ****If you are on the Network or connected to VPN**** please follow these directions to change your password: 
		    Please press Ctrl + Alt + Del -> Change password
            IF YOU ARE NOT CONNECTED TO THE VPN OR NETWORK YOU WILL HAVE TO CHANGE YOUR PASSWORD THROUGH OFFICE 365 (office.com)
            Please reach out to Help@Contoso.com and open a ticket if you have a problem. 
			
			
			Please remember your passwords must meet the following requirements:
			-Passwords can not be reused in the last 5 cycles
			-Not contain the user's account name or parts of the user's full name that exceed two consecutive characters
			-Be at least six characters in length
			-Contain characters from three of the following four categories:
			-English uppercase characters (A through Z)
			-English lowercase characters (a through z)
			-Base 10 digits (0 through 9)
			-Non-alphabetic characters (for example, !, $, #, %)" 
  if ($daystoexpiry -lt 9 ) { 
    $emailTo = "$mail" 
	    $subject = "Your Network password will expire in $daystoexpiry day(s) please change your password."   
    Send-MailMessage -To $emailTo -From $emailFrom -Subject $subject -building $body -SmtpServer $smtpserver 
    Write-Host "Email was sent to $mail on $today" 
    Add-Content C:\logs\maillog$logdate.txt  "Email was sent to $mail on $today" 
  } 
} 
Send-MailMessage -To "it_alerts@contoso.com" -From "expiringpasswords@contoso.com" -Subject "Password change log for $today" -building "This is the log from $today" -Attachments "C:\logs\maillog$logdate.txt" -SmtpServer $smtpserver