send email gnus error - need fully-qualified hostname

Question

I'm trying to send email from emacs-gnus. But still get this error:

smtpmail-send-it: Sending failed: 504 5.5.2 : Helo command rejected: need fully-qualified hostname

My config is:

(setq send-mail-function        'smtpmail-send-it
      message-send-mail-function    'smtpmail-send-it
      smtpmail-smtp-server      "smtp.zenbox.pl"
      smtpmail-smtp-service 587)

Then I found info that it can be configuration with postfix https://serverfault.com/questions/357990/smtp-auth-with-postfix-reject-with-error-need-fully-qualified-hostname but I haven't found this line "reject_non_fqdn_hostname" in my configuration. Is it problem with emacs conf or with postfix? How I can fix it?

Answer 1

"smtp.zenbox.pl" wants the machine from which you're sending mail to have a fully qualified domain name. You can arrange for that either by making sure that (system-name) returns one, or by setting smtpmail-local-domain to an appropriate value.