internal/functions/get-tenantfromemail.ps1

<#
.SYNOPSIS
Get the tenant from e-mail address
 
.DESCRIPTION
Get the tenant (domain) from an e-mail address
 
.PARAMETER Email
The e-mail address you want to get the tenant from
 
.EXAMPLE
PS C:\> Get-TenantFromEmail -Email "Claire@contoso.com"
 
This will return the tenant (domain) from the "Claire@contoso.com" e-mail address.
 
.NOTES
Author: Rasmus Andersen (@ITRasmus)
Author: Mötz Jensen (@Splaxi)
 
#>

function Get-TenantFromEmail {
    [CmdletBinding()]
    [OutputType('System.String')]
    param (
        [string] $email
    )

    $email.Substring($email.LastIndexOf('@') + 1).Trim();
}