I have my first ZCS server running. ( I hope this is the right forum/thread)
One account works via webmail, zimbra desktop and thunderbird.
When I want to send a mail from Outlook (account set up as IMAP with SMTP to the public address of the ZCS server port 587 with TLS encryption)
I cannot send mail from outlook.
in zimbra.log it gives me:
Sep 26 11:52:06 mail postfix/smtpd: NOQUEUE: reject: RCPT from <public address of outlook pcs internet connection>[220.127.116.11]: 554 5.7.1 <public address of outlook pcs internet connection>[18.104.22.168]: Client host rejected: Access denied; from=<firstname.lastname@example.org> to=<email@example.com> proto=ESMTP helo=<laptop's windows hostname>
In the admin console I disabled under Global Settings the reject_non_fqdn_sender check, but no difference.
From thunderbird and zimbra desktop and zimbra webmail, I do not have this problem..