I have interesting problem,
have HMS with 2 domains and some acccounts,
one domain has problem to send mail to customer, message returns to sender, but if i tried to send it from second domain, mail arrives to customer.
Customers mailhoster sais, thas is problem at our side, because of valid identification and verification.
Here is returned message:
Have you any ideas, what can be wrong? If I know to anyone else messages going fine.Your message did not reach some or all of the intended recipients.
Sent: Mon, 9 Jan 2018 14:21:24 +0000
Subject: some subject
The following recipient(s) could not be reached:
Error Type: SMTP
Remote server (18.104.22.168) issued an error.
hMailServer sent: RCPT TO:<email@example.com>
Remote server replied: 550-Verification failed for <firstname.lastname@example.org>
550 Sender verify failed