You encounter the issue of outbound emails from sender domains not registered as valid HES domains not being accepted or forwarded to their recipients.
Trend Micro implemented this change on May 13, 2009. HES users who have outbound mail scanning enabled can no longer send an email through their outbound mail transfer agents (MTAs) if the sender's domain is not registered with HES.
If a sender domain not registered with HES is sent, the sender will get a non-delivery receipt (NDR) with the Sender address rejected: Access denied error.
To enable sender domains that are not registered with HES to send emails, add the sender's domain that you own or manage as one of the managed domains in your HES account.
For customers who have sender domains (that they do not own or manage) allowed to relay through their mail server, and to allow them to be sent, contact Technical Support and request these domains to be whitelisted.
HES users that do not have outbound mail scanning enabled but who want to to have it enabled must contact Technical Support and provide the following information:
- Company name
- Requestor's name
- Requestor's phone number
- Requestor's email address
- Valid HES activation code
- Domain name registered with HES
- Public IP address of the outbound MTA
