but beware: there are a lot of services by overzealous colleagues who 'check' email addresses and reject '+' (for religious reasons?). Email addresses can be

but beware: there are a lot of services by overzealous colleagues who 'check' email addresses and reject '+' (for religious reasons?). Email addresses can be quite complex (cough), what those may never have come across. See 6.1 in RFC822.