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Global Information Security Societyfor Professionals of PakistanTopic : Email Security Simplified – Lesson 1Speaker’s Name : Shahzad Subhani

Agenda What is Email SecurityWhy Email Security ?How Email WorksEmail Protocols ,Ports and Key TermsSMTP Response CodesEmail Related DNS RecordsTypical Email ScenarioQuick Demonstration for DNS RecordsGlobal Information Security Society for Professionals of Pakistan2

What is Email Security Email security can be defined as the use of various techniques to keepthe sensitive information in email communication and accountssecure. To Understand Email Security , One Needs to Understand on HowEmail Works and what are the different elements that comprise of anEmail System . The Whole Objective of Email Security is to ensure that the Usersreceive secure and good emails and they should not waste valuablecompany time in filtering good email from the bad emails .Global Information Security Society for Professionals of Pakistan3

Why Email Security Enterprise rely heavily on email for daily business communications Email is Most common vector to attack an enterprise by whichenterprises are attacked. Most of the Enterprise business communication is done via Email andpeople exchange millions of files every day via Email Messages Email is a common entry point for attackers looking to gain a footholdin an enterprise network and attack valuable business data. Most of the attackers use Email as their First Priority attack vectorGlobal Information Security Society for Professionals of Pakistan4

How EmailWorksCourtesy : https://www.oasis-open.org/khelp/kmlm/user help/html/how email works.htmlGlobal Information Security Society for Professionals of Pakistan5

Protocols/Ports and Key Terms SMTP Stands for Simple Mail Transfer Protocol SMTP Port is 25 SMTP was initially defined in RFC 821 which was later revoked by RFC2821 (https://www.ietf.org/rfc/rfc2821.txt ) SMTPS ( SMTP Secure via TLS OR SSL and Port is 567) however it notused widely TLS ( Transport Layer Security) is used to Send email Securely(Encrypted) between Two Servers by issuing STARTTLS Command MTA ( Mail Transfer Agent) MUA ( Mail User Agent)Global Information Security Society for Professionals of Pakistan6

SMTP Response CodesSMTP Response Codes is a way for Servers to communicate or talk witheach Other . If an Email is not being delivered , always look at theResponse code given by Destination Server . Here are some commonSMTP Response Codes . 220 –SMTP Service Ready 221 – Service Closing 250 – Requested Action taken and Completed 421 – Please Try Later OR Service is not available 50x – Server Could not recognize the command 550 – No Such User Here OR User Mailbox not AvailableGlobal Information Security Society for Professionals of Pakistan7

SMTP Related DNS Records MX Record - A DNS Record created to show which server will receive emails foran organization MX Record Priority - The Smaller it is , The Higher the Priority is SPF Record : A DNS Record which will show which IP Addresses are authorizedto send email on an organization’s behalf DKIM (DomainKeys Identified Mail): Digitally Signing all outgoing emails witha Private Key to ensure that Email is actually sent by the Sender Domain itselfand it is not spoofed Standard DMARC (Domain-based Message Authentication, Reporting & Conformance) :It is an Email Authentication, policy, and reporting protocol. It builds on thewidely deployed SPF and DKIM protocols .Global Information Security Society for Professionals of Pakistan8

Typical Email Scenario This SMTP example shows mail sent by Smith at host bar.com, to Jones, Green, and Brown at host foo.com. Here we assume that hostbar.com contacts host foo.com directly. The mail is accepted for Jones and Brown. Green does not have a mailbox at host foo.com.S Shows Responses from SMTP Server and C shows Responses from Client .S: 220 foo.com Simple Mail Transfer Service ReadyC: EHLO bar.comS: 250-foo.com greets bar.comS: 250-8BITMIMES: 250-SIZES: 250-DSNS: 250 HELPC: MAIL FROM: [email protected] S: 250 OKC: RCPT TO: [email protected] S: 250 OKC: RCPT TO: [email protected] S: 550 No such user hereC: RCPT TO: [email protected] Courtesy : RFC 2821Global Information Security Society for Professionals of Pakistan9

Demonstration/Explanation of DNS Records Quick Demonstration using few Websites like MX Toolbox (https://mxtoolbox.com/) SPF Record Checker ( https://www.dmarcanalyzer.com/spf/checker/ ) NslookupGlobal Information Security Society for Professionals of Pakistan10

Next LectureIn my next video , I will talk about these Topics . If you want to add anymore topic , please mention that in the comments section . Email Attacks Types Email Relaying Email Spoofing Email Header AnalysisGlobal Information Security Society for Professionals of Pakistan11

SMTP Response Codes SMTP Response Codes is a way for Servers to communicate or talk with each Other . If an Email is not being delivered , always look at the Response code given by Destination Server . Here are some common SMTP Response Codes . 220 –SMTP Service Ready 221 –S