Understanding Email: Definition, Sending Process

Email: Definition and Function

• Email allows for the sending and receiving of messages across the Internet.
• It shares similarities with traditional mail but possesses distinct differences.

How Email Works: The Simplified View

• From a user's perspective, sending an email involves entering the recipient's address, composing a message, and clicking "Send".

The Reality of Email Transmission

• Sending an email involves navigating a complex network, making the outcome uncertain.
• The sender is a person using a company account to send an email
• Step A: Sender creates and sends an email
• A Mail User Agent (MUA) is the application the sender uses to compose and read emails, like Eudora or Outlook.
• Step B: Sender's MDA/MTA routes the email
• The sender's MUA sends the email to a Mail Delivery Agent (MDA) for routing.
• The sender's Mail Transfer Agent (MTA) commonly handles MDA responsibilities.
• Common MTAs that perform MDA functions include Sendmail and qmail.
• The MDA/MTA either directs the email to local mailboxes or forwards it if it's not locally addressed.

Network Cloud

• Email traverses a network cloud that can be a company network, an ISP, or the Internet.
• The network cloud may include mail servers, DNS servers, routers, and various other devices and services.
• Heavy loads can slow processing, and maintenance can cause temporary unavailability.
• MTAs in the network cloud must properly identify themselves via the Domain Name System (DNS) for email delivery.
• Firewalls, spam filters, and malware detection software protect these devices, potentially bouncing or deleting emails.
• Email deletion by software is often silent, leaving the sender unaware of the failure.

Email Service Providers

• They and other high-volume email companies use private network clouds with multiple mail servers.
• These organizations route email through a central gateway server that redistributes it to available MTAs.
• Secondary MTAs usually await the primary MTA's availability before transferring messages.
• Step D: Email Queue
• Emails addressed to others companies enter a queue with other outgoing emails. If there is heavy traffic, the email is delayed until the MTA can processes it.
• Step E: MTA to MTA Transfer

The Sending MTA's Role

• The sending MTA manages all aspects of mail delivery until the receiving MTA accepts or rejects the message.
• The Internet network cloud routes emails via a host-to-host server chain.
• Each MTA in the network cloud consults the Domain Name System (DNS) to determine the next MTA in the chain.

Factors Influencing Email Route

• The precise route depends on server availability and the ability of an MTA to accept email for the specified domain.
• Server availability affects the path, so emails from the same host to the same recipient can take different routes.

Spammers

• Spammers may specify parts of the path, routing messages through relay servers to hide the origin.

Locating Recipient's IP Address

• The MTA must navigate the Domain Name System (DNS) to find the recipient's IP address and mailbox.
• This process starts with root nameservers at the top-level domain (.tld) and progresses to domain nameservers and local domain nameservers.

DNS Resolution and Transfer

• There are 13 root servers that serve the top-level domains (e.g., .org, .com, .edu, .gov, .net).
• MTA can bypass the step because it already knows which domain name servers handle requests for these .tlds.
• The MTA can bypass some steps if it already knows the domain name servers for specific .tlds.
• The MTA queries the DNS server for Mail Exchange (MX) servers associated with the subdomain or local host.
• The DNS server sends back a prioritized list of MX servers in an MX record.
• An MX server acts as an MTA but is named MX server to the DNS server.
• The MTA contacts the MX servers on the MX record in order of priority until it finds the designated host for that address domain. The MTA asks if the host accepts messages for the recipient's username at that domain (i.e., [email protected]) and transfers the message.
• Step F: Firewalls, Spam and Virus Filters
• The described transfer process is often simplified, as emails may pass through multiple MTAs and at least one firewall.
• Firewalls may use spam and virus filters to check messages for spam or malware.
• Virus-containing messages are quarantined, and the sender is notified.
• Spam messages are often deleted without notifying the sender.

Spam Detection and Actions

• Spam detection is hard because spam can take different forms
• Spam filters use many different criteria and can misclassify messages, especially from mailing lists.
• If an expected email from a list or automated source is missing, a spam filter at the receiver's ISP or company is the likely cause.

Delivery

• Emails that pass spam filters are then accepted for delivery by the receiver's MTA.
• The MTA uses a local MDA to deliver the email to the recipient's mailbox, where it remains until retrieved by the recipient's MUA.

RFCs: Defining Email Standards

• Email standards are defined in documents called "Request For Comments (RFCs)".
• RFCs are available on the Internet Engineering Task Force (IETF) website.
• RFCs form a complex set of standards that provide detailed information about email.

Pertinent RFCs

• RFC 822: Standard for the Format of ARPA Internet Text Messages
• RFC 2821: Simple Mail Transfer Protocol

Email's Similarity to Regular Mail

• The design of email construction and delivery models regular mail.

Email Message Structure

• An email message is structured like a letter inside an envelope.
• The email envelope header functions like a hardcopy letter's envelope, though some information is in the message header.
• The message header has information not found on real-world envelopes but it is essential for email delivery.
• The envelope header is usually hidden, while the message header is visible.
• Together, both headers make up the full header.

Message Header Fields

• Email message headers usually include the 'From:', 'To:', 'Cc:', 'Date:' and 'Subject:' fields.
• These fields are like regular mail but use email addresses to identify sender and recipients.

Date Field

• The 'Date:' field is added by the sender's MUA and is only as accurate as the sender's computer clock.

Subject Field

• The 'Subject:' field is used in email because differentiates it from other emails based on the 'From', 'To', and 'Date' fields

Return-Path Explanation

• Email contains more information about delivery than regular mail's postmark.
• MTAs add timestamps and location data, including 'Received' fields and the 'Return-Path' which has info about the sender.
• The 'Return-Path' which is the "envelope sender", indicates who sent a message and where bounces are sent.

Received Field

• Each MTA adds data to a 'Received' field as it accepts an email for transfer, including a message ID, timestamps, and the sending MTA's identity.
• Following the 'Received' entries in order reveals the path back to the originating MTA.

Importance of Sending MTA Identity

• Information about the true identity of the sending MTA is valuable for troubleshooting spam or malicious emails.
• Spammers often provide false identities in 'From' and 'Reply-To' fields.
• The receiving MTA verifies the originating MTA's hostname against a unique IP address.

Reply-To Field

• The 'Reply-To' field contains an address for replies, similar to a return address on regular mail.
• Automated notifications may use a different 'Reply-To' address for handling bounced messages.
• Spammers and malicious emails may contain false information in 'From:' and 'Reply-to' fields.

Troubleshooting Email Issues

Messages Eaten by Spam Filters

• Spam filters eat messages silently because sending MTAs will already have successfully completed the transfer to a firewall server.

Message Failures

• Message failures will not fail silently when an MTA attempts to transfer a message.

MTAs Reliably Complain When Transfers Fail

• Except when a message was mistaking for spam, or languishing in a moderation or archive update queue, users will know what happened to their message, because MTAs reliably complain when transfers fail.
• A sending MTA can encounter two types of transferring problems: transient or permanent failures.

Transient Failures

• A transient error occurs, the MTA will hang onto the message, periodically retrying the delivery until it succeeds or fails, or until the MTA decides that the transient issue is really a permanent condition.

Permanent Failures

• MTA cannot deliver the message (fatal error message or failed to complete the transfer after repeated attempts), it bounces the message back to the sender.
• When the mailing list is the sender, the bounce can be handled by automated bounce-handling software.

Types of Email

• Different types of emails will fall into different categories, standalone or campaigns.
• Example: a welcome email might come first in a series of emails and a marketing email might be an entry point to the top of your sales funnel.

Email Strategy

• Experiment with various email types to determine the best approach for your email marketing strategy.
• Automated email marketing campaigns with trigger-based notifications work better than email blasts.

Product Release Email

• Refrain from including every detail about a product, instead provide the takeaway and link to your website/blog. Example: new feature email from Wistia that promotes the new feature in the subject line, “A/B testing is here! Ah, that new feature smell."

Privacy Policy Update Email

• Update emails in accordance with GDPR without fluff, be brief and crystal clear.
• Updates should be bulleted and bolded to easily get the idea of what's changing

Event Email

• For event emails, keep your desired action in mind, like adding it in their calendar, an RSVP form or tickets purchase.
• The first email often has more info about the event, and the other emails should push to the website.

Educational Email

• Provide educational information to continue your relationship with recipients without being too pushy.
• Providing an article or guide to track engagement and click to open rates is great.

Promotional Email

• Percentage-off discounts in the subject line performed worse than those without percentage_discounts.

Transactional Email

• It is how you communicate with your subscribers, expand your customer base, and drive revenue.
• Transactional email boasts the highest open rates to driving recipients..
• Here are some examples of transactional email:
• Password resets
• Confirmation emails
• Shipping notifications
• Appointment reminders
• Invoice emails
• Order confirmations
• Receipt emails
• Account activity notifications
• Feedback requests
• Licensing updates

Marketing Email

• Marketing emails are strategic and targeted emails sent to a specific audience to promote products, services, etc.
• Value: Marketing emails are carefully crafted to deliver value and resonate with the recipients by using persuasive content, compelling visuals, and clear calls to action.
• Segmentation: Effective marketing emails are often segmented based on factors like demographics, behaviors, purchase history, or engagement level.
• Personalization: Personalized marketing emails use the recipient's names, preferences, or past interactions to create a more experience.
• Call to action: Marketing emails aim to guide recipients toward a specific goal, such as making a purchase, signing up for a webinar, etc.

Types of Marketing Emails:

• Newsletters
• Promotional emails
• Drip campaigns
• Abandoned cart emails
• Re-engagement emails
• Announcement emails
• Offer emails, coupons, limited-time offers, or other valuable content.

Welcome Email

• Welcome emails mark your recipients' first interaction with your brand shaping their first impression.

Key Objectives of a Welcome Email

• Purpose: Remind email subscribers of why they're joined while expressing gratitude for loyalty.
• Interaction: Engagement by presenting an exclusive offer or a call to action.
• Expectations: Establish the tone and expectations for future email communications/

Abandoned Cart Email

• When someone adds items to an online shopping cart but leaves without buying them, that's called an abandoned cart.

Re-Engagement Email

• A re-engagement email has one goal: to ask inactive subscribers if they still want your emails. Segmentation: Divide the list into engaged recipients and those inactive for around 1-2 months, on crafting content.
• Friendly inquiry: Reach out to inactive readers politely to understand their disinterest.
• Standout email subject line: Create subject lines that grab attention and differ from regular emails.
• Preference center: Let recipients adjust email frequency or content, allowing unsubscribers to share reasons.
• Incentives and offers: Motivate engagement with offers such as discounts, personalized recommendations., and loyalty programs.

Feedback Request Email (or survey email)

• A email to gather insights, opinions, and suggestions their audience
• Examples:
• Customer support feedback
• Website/user experience feedback
• Event or webinar feedback
• Product improvement surveys
• Abandoned cart feedback
• Employee feedback

Announcement Email

• Used as direct communications for sharing updates with subscribers, customers, or stakeholders.

Thankyou Email

• Thank-You emails express gratitude and appreciation to customers, subscribers, or provide personalized and heartfelt communication.

Holiday Greetings Email

• This share festive designs, heartfelt content, and inclusive language and personalized and engaging subject lines.

Referal Email

• Referral emails enlist current customers, subscribers, or contacts to refer new customers with incentives

Testimonial Email

• Testimonial emails leverage success narratives and authentic experiences to sway potential customers.

Cross-Sell Email

• introduce complementary or related emails such as related products or other services to existing customers based on their previous purchases

Personal Outreach Email

• is used to build personalized communication with customers or industry contacts such as through feedback requests for product demonstration

Onboading Email

• Used to introduce a company to new members through instructional guides, tutorials, tips, and best practices

Newsletter Email

• Elevate blogspot and Youtube Videos through this method

User generated content

Email Security

• Is an effective communication method, essential in many ways, and has to be protected.

Steps to Secure Email

• Set a strong password and use it whenever possible when accessing email data and accounts
• Set up two-factor identification whenever it is available
• Use email encryption with S/MIME
• Keep all software completely up to date

More Steps

• Beware of all types of phishing scams
• Use a trust worthy email service with safe measure
• Use a VPN
• Upgrade your application regularly

Email Security Protocols

• To protect communications
• The policy needs to be able to outline what is appropriate
• Passwords need to be required and authentication set up
• Encryption is required
• Protection from all viruses is manditory

Further Precautions

• Detection and Retention policy should include the the removal of email
• Training for email safety
• The steps to report any incidents
• Monitoring steps
• Ensure all security law is applied to it

Confidential Gmail

• A function in Gmail.com

Access Before Deletion

• Remove access before the data is set to be deleted
• Prevents receivers from any unintended issue

Malwares

Removal

• Malwares are removed

Worms

• Can replicate and spread

Types of Malwares

• Ransomeware is also used to demand money
• Fileless Malwares never download so they cant be found
• Rootkit is used ro gain control of files
• Keyloggers keep track od recordings

Anti maleware functions

• Signature Scan
• Heuristic Analysis
• Real time behavioural analysis