Lauriel is reviewing the configuration for an email server in her organization and discovers that there is a service running on TCP port 993. What secure email service has she most likely discovered?

Secure IMAP’s default port is TCP 993. Laurel can easily guess that the system offers a TLS-protected version of IMAP for clients to use to retrieve email messages. The default port for secure POP is 995, and for secure SMTP the default port is 587. S/MIME does not have a specific port, as it is used to encrypt the content of email messages.