How to find this setting:
Your Email Software > Trend Micro > Settings > Approved Senders
Not all versions of Trend Micro security software include this feature.
Use the List of Approved Senders to ensure that messages sent from specific email accounts will not get identified as spam. Remember to click OK after making any changes.
Click Update from contacts to import all email addresses from your default lists of contacts into the Approved Senders list.
Click Add to put a single email address on the list.
Click Edit to change an email address that you have selected on the list.
Click Remove to delete an email address that you have selected from the list.
For your convenience, mark the check box next to Whenever you send email, add the address to the list of Approved Senders automatically.
If you edit or remove the email address of an approved sender, messages from that address could potentially be identified as spam. Think carefully before changing or removing any email address.