How Email Really Works: A Journey from Send to Inbox

Email remains a cornerstone of digital communication, powering everything from personal chats to critical business exchanges. But what happens behind the scenes when you hit “send”? The journey from your device to the recipient’s inbox involves a sophisticated chain of servers, protocols, and checks. For those hosting email services, understanding this process can optimize deliverability and troubleshoot issues effectively. For example, if your ava.hosting-hosted business email gets flagged as spam, knowing the role of SMTP and DKIM can help you fix it fast. This guide breaks down each step of email delivery, revealing the intricate systems that keep your messages flowing seamlessly.

1. Composing and sending email

When you write an email using an email client (such as Outlook, Thunderbird or a webmail interface), the process starts with formatting the message by your device – including the sender, recipient, subject, subject, body and any attachments.

Once you click “Send,” your email client transmits the message to an outgoing mail server, usually using SMTP (Simple Mail Transfer Protocol).

2. The SMTP server processes the request

The e-mail is forwarded to the SMTP server, which functions as a digital post office. It reads the recipient’s domain (the part after the @ symbol) and uses DNS (Domain Name System) to look up the correct MX (Mail Exchange) records for the destination server.

This tells your server where to deliver the message.

3. Relaying and routing

In many cases, the SMTP server relays the email to another SMTP server closer to the recipient, especially if you have different email providers. These hops are fast and invisible to the user, but involve routing logic, spam checks, and sometimes greylisting.

During this process, the message may be scanned, queued or temporarily delayed depending on server load or security rules.

4. Delivery to the recipient’s mail server

Once the recipient’s mail server receives the message, it checks it against its own spam filters, security policies and user settings. If the email passes all checks, it is stored in the user’s mailbox on the server.

The message remains on the server until the recipient opens their e-mail client or application.

5. Retrieving mail (POP3 or IMAP)

To read the e-mail, the recipient’s device connects to the e-mail server using either:

• POP3 (Post Office Protocol v3): downloads the email and (usually) deletes it from the server.
• IMAP (Internet Message Access Protocol): Synchronizes messages and folders between server and device, ideal for access from multiple devices.

Most modern clients use IMAP for better flexibility and real-time synchronization.

6. Message display

Finally, the email is rendered in the recipient’s client – including formatting, HTML, images and any attachments. At this point, it behaves like any other digital message.

Behind the scenes, it may include metadata such as headers, IP paths, DKIM/DMARC/SPF validations and more.

Summary: Email delivery flow

• The user composes and sends the email.
• SMTP server processes the message.
• DNS/MX records are checked to find the recipient’s server.
• E-mail is routed, possibly forwarded and delivered.
• Stored in the recipient’s mailbox.
• Retrieved via IMAP or POP3.
• Displayed to the end user.
• Conclusions

Conclusion

Email’s simplicity hides a complex dance of protocols—SMTP, DNS, IMAP, and more—working together to deliver your messages reliably. Understanding this process unlocks better email management, from boosting deliverability to resolving issues like spam flags. For instance, configuring DKIM on your ava.hosting email server can prevent rejections, while choosing IMAP ensures seamless access across devices. By mastering these steps and leveraging ava.hosting’s dependable infrastructure, you can ensure your emails reach their destination swiftly and securely, keeping communication smooth and effective.