I am trying to create SharePoint hostnamed site using the below PS command but its failing in -owneremail parameter and unable to recognize ".systems" TLD (top-level-domain) - though its a valid TLD.
New-SPSite http://test.contoso.com -OwnerAlias "contoso\joe" -HostHeaderWebApplication http://test.portal.local -Name "Test" -Template "STS#0" -OwnerEmail joe@contoso.systems
Error: New-SPSite : The e-mail address joe@contoso.systems is in