could not send the email, because the user is delegated or external.
previous response is correct. BC doesn't allow user with certain types of licenses to send emails from BC. Unfortunately, those include delegated admin (usually consultants/support team from the partners) and external accountants. I don't believe guest users could send out email as well. If you view the user card, their email is not the regular work email but with symbols like # and so forth.
could not send the email, because the user is delegated or external.
Hi, as mentioned, that is by design. If you have suggested improvements and some wanted functions, you could send the feedback into the idea forum, add a new idea or vote for existing ideas.