CompTIA: Advanced Security Practitioner (CASP) Exam Prep

Answer: D - An e-mail virus filter verifies that files received by an SMTP server contain no suspicious files.

Key Takeaway: SMTP is the primary protocol used in e-mail. An SMTP virus filter checks all incoming and outgoing e-mails for suspicious code. If a file is potentially infected, the scanner notifies the originator and quarantines the file.