04/16/14

NT2670, Email and Web
Unit 4 Assignment: SMTP Security
1. List and describe three SMTP server security threats?
a. Viruses can erase files, cause computer crashes and destroy information or get information.
b. Spam email is a term used to describe messages sent in bulk or incoming emails that are received without consent.
c. Directory harvest attacks (DHAs) is an attempt to determine the valid e-mail addresses associated with an e-mail server so that they can be added to a spam database.
2. List three suggestions to harden SMTP server security?
a. “Disable open relaying on all SMTP virtual servers: Open relay on your Exchange Server allows other Email servers to use your server as a gateway to others. This allows others to send spam Email which appears to be originated from your address, therefore you will be identified as a spam source.” (Ehamouda, 2009)
b. “Prevent anonymous access on internal SMTP virtual servers and dedicated SMTP virtual servers for IMAP and POP clients: Because all Exchange servers within your organization authenticate with each other to send mail, you do not need to enable anonymous access on your internal Simple Mail Transfer Protocol (SMTP) virtual servers. Additionally, all Post Office Protocol (POP) and Internet Message Access Protocol (IMAP) clients authenticate with your SMTP virtual server, so anonymous access is not required on a server that is used exclusively by POP and IMAP clients.” (Ehamouda, 2009)
c. “Restricting Submissions to Distribution Lists and Users: Restrict who can send e-mail messages to an individual user or a distribution list. Restricting submissions on a distribution list prevents non-trusted senders, such as unauthorized Internet users, from sending mail to an internal-only distribution list.” (Ehamouda, 2009)
3. In what scenario would you require TLS encryption?
a. Whenever you are sending