Symantec's logo is the default for the encrypted email notifications and the secure portal sign in page. This can be updated to a provided logo by the company.
In order to change the logo for secure portal and notification for encrypted emails, create a support case with Symantec Technical Support. Provided the desired logo as an attachment to the case. The logo should be in a .gif file and have the following dimensions:
225x88px - Size for the secure portal
150x68px - Size for email notifications