Use powershell to validate Email address

A time comes along when you need to validate an Email address using Powershell. Created a function just for this purpose as an introduction to how you may create advanced functions in powershell.

	function Assert-EmailAddress
	{
	<#
	.Synopsis
	Validate Email address
	.DESCRIPTION
	Use this cmdlet to validate Email addresses.
	.EXAMPLE
	Assert-EmailAddress -StringEmail "test@domain.com"
	Outputs True
	.EXAMPLE
	"tore.somedomain.dom" | Assert-EmailAddress
	Outputs False
	.EXAMPLE
	$object = "" | Select-Object -Property Mail
	$object.Mail = "test@domain.com"
	$object | Assert-EmailAddress
	Outputs True
	.INPUTS
	[string]
	.OUTPUTS
	It outpus a boolean value indicating if it is a valid Email Address
	.NOTES
	Use at your own Risk!
	.COMPONENT
	General scripting
	.ROLE
	Mail space
	.FUNCTIONALITY
	Validating Email Addresses
	#>
	[OutputType([bool])]
	[cmdletbinding()]
	Param(
	[Parameter(
	Mandatory=$true,
	ValueFromPipeline=$true,
	ValueFromPipelineByPropertyName=$true,
	ValueFromRemainingArguments=$false
	)]
	[ValidateNotNullOrEmpty()]
	[Alias("Email","Mail","Address")]
	[string]$StringEmail
	)
	Begin
	{
	$f = $MyInvocation.InvocationName
	Write-Verbose -Message "$f - START"
	}
	Process
	{
	Write-Verbose -Message "$f - Asserting email $StringEmail"
	try
	{
	$Email = New-Object -TypeName System.Net.Mail.MailAddress -ArgumentList $StringEmail
	if($Email.Address -eq $StringEmail)
	{
	Write-Verbose -Message "$f - Valid email address $StringEmail"
	return $true
	}
	else
	{
	Write-Warning -Message "$f - Invalid email address $StringEmail, was parsed to $($Email.Address)"
	return $false
	}
	}
	catch
	{
	Write-Warning -Message "$f - Invalid email address $StringEmail"
	return $false
	}
	}
	End
	{
	Write-Verbose -Message "$f - END"
	}
	}

view raw Assert-EmailAddress.ps1 hosted with ❤ by GitHub

This function will “validate” an email address using the System.Net.Mail namespace and output an Boolean value indicating if an string is a valid address. It uses a structure and style that is my personal preference. Feel free to comment if you like.


Basic learning points

• It is an advanced function
• It supports the pipeline
• It displays how to create an instance of a .Net class

Cheers

Tore