Recently I have setup ZCS successfully; now I want to send mail to external accounts, but get some errors.
In Configuration -> Server -> MTA, at the option "Relay MTA for external delivery" I put the IP of the SMTP server we usually use. That server works with SMTP and user autentication.
When sending emails to addresses within that server, they arrived. However when sending to accounts at Yahoo, Gmail and other I get the following errors:
<email@example.com>: host 18.104.22.168[22.214.171.124] said: 553 sorry,
that domain isn't in my list of allowed rcpthosts (#5.7.1) (in reply to
RCPT TO command)
<firstname.lastname@example.org>: host 126.96.36.199[188.8.131.52] said: 554 5.7.1
<email@example.com>: Relay access denied (in reply to RCPT TO
What should I do to bring ZCS to send email to external accounts successfully?
Thanks for your support,