To improve performance and security on Trellix DLP Network Prevent appliances dedicated to analyzing web traffic, close the SMTP ports.
In ePO - On-prem, open the Policy Catalog.
Select the DLP Appliance Management product, select the Trellix DLP Network Prevent Email Settings category, and open the policy that you want to edit.
In the SMTP field, deselect Enable SMTP and Enable Authenticated Mail Submission (Uses SMTP AUTH over TLS on port 587).
Click Save.