When an infected E-Mail is detected, it is moved in a quarantine repository. This allows you search this repoitory and check every suspected E-Mail. You can also delete it, or resend it if it was mistakenly put in quarantine.
If you are using amavisd-new/SpamAssassin you will be able to manage both Spams and Viruses. Note that if you use ClamAV-Milter, Qmail-Scanner or MailScanner you will not be able to view the virus name in the quarantine listing.
You may also manually purge the quarantine directory or choose the frequency of the automatic purge.