Getting error "554 transaction failed spam message not queued" while sending mails to external domains
Our mail gateway audit logs is giving the message 554 transaction failed spam message not queued while sending mails to certain specific external domains. I searched a lot on the internet as well as this forum but could not find anything useful.
Below are my observations:
1. Our domain/IP is not in any blacklist.
2. The recepient's domain/IP is not blacklisted either.
3. I am able to send mails to the recepient's domain from other domains other than my local domain.
4. The messages are not in Spam Quarantine.
5. I get the same message from the command line as well:
We are running SMG version 9.5.3-3.
I suspect our IP/domain is blacklisted by the recepient's mail gateway and hence it is not accepting mails from us. Please let me know this assumption is right and assist me with this issue.