Help with making a popup dialog box with large text area instad of a read-host action

[CmdletBinding()]
param ($computerissue = (Read-Host "Please state the problem you are having"), 

   $subject = "### Incoming Ticket From User: $env:USERNAME Computer: $env:COMPUTERNAME ###",
   $to = "NCIT.Help@us.af.mil",
   $bcc = '',
   $body = $Collection,

  [string]$ErrorLog = 'c:\powershell\useful\errorlog\retry.txt',

   [switch]$LogErrors
    )
 [Array]$Collection = foreach($computer in $computerissue)

 {

$body = New-Object -TypeName PSObject -Property @{
   Problem = $computer;
   
   } | format-list | out-string

 #$obj | convertTo-csv | out-string

 #$obj = $body
 #$Collection = [string]$body


 #[String]$Collection

 [string]$body

 Start-Process -FilePath "mailto:$to&subject=$subject&body=$body"
}


$Collection