Email accounts that send large volumes of outbound spam messages may lead to the blocking of the sender address or sender IP by the internal global blocked list or by third-party Real-time Block Lists.
If the sender/recipient is blocked by internal global blocked list, you can do the following steps:
- Perform an initial check.
- For Sender blocked (block list), refer to Managing the Approved/Blocked Senders List of Trend Micro Email Security (TMEMS to check if the sender's email address is on the Blocked Senders List. You may also go to Dashboard, select the managed domain, and choose Outgoing for Direction. Click on Top Statistics and look for Top Spam to check if the sender is on the top list.
- For Sender IP blocked, you may do an IP Reputation Check.
- Inform the sender/recipient that their email address is identified to have suspicious activity.
- Ensure that the IP/email address is safe and not compromised. If the account has been compromised, immediately change the account password.
- Report the IP/email address to Trend Micro Technical Support for further analysis and unblock requests.
- Submit a sample mail if required as additional information to the investigation.