Thank you all so much for your answers. In man mail(1) it is not clear to me that mail(1) is not for use outside a local network. In http://openbsd.das.ufsc.br/nl/mail.html It says: " Many subscribers and developers read their mail on text-based mailers (mail(1), emacs, Mutt) " I do understand that some users of OpenBSD do use mail(1) or Mutt as an email client.
I do not want (now) to build a mail server. I would like to use an email client to receive and send and read email to and from a mailserver at an ISP. Why do I want to use mail(1) as an email client? I try to understand openBSD by playing around with it. I did learn a lot in this discussion. Thanks again.
