Email Security.cloud
"Email Security.cloud" is a product working in combination with "Symantec Messaging Gateway" as part of a range of services offered by Broadcom. It features spam filtering, firewall protection, and block lists. Mail is routed through mailservers owned by them (messagelabs.com) before it's passed along to the recipient domain's mailservers for final delivery. The recipient is able to manage a lot of delivery settings such a allow lists, so it helps to ask the recipient to run the described debugging tests in the user guide to identify and resolve delivery issues, as there is no way to contact the vendor directly.
Codes
- 450↑
- 450 Requested action aborted [9] #-#, please visit https://knowledge.broadcom.com/external/article?legacyId=TECH246726 for more details about this error message.
- 553↑
- 553 Message filtered. Refer to the Troubleshooting page at http://www.symanteccloud.com/troubleshooting for more information. (#5.7.1)
- 553 you are trying to use me [xx.messagelabs.com] as a relay, but I have not been configured to let you [x.xx.xx.xx, example.com] do this. Please visit www.symanteccloud.com/troubleshooting for more details about this error message and instructions to resolve this issue. (#5.7.1)