If you’ve ever wondered how email is sent and what happens after you click Send, this guide will walk you through the journey your email takes before it reaches the recipient’s inbox.
You’ll learn how email travels between servers, the role of your email application, and the technologies that make reliable email delivery possible.
By the end of this guide, you’ll have a clear understanding of the email delivery process and the common protocols involved, helping you better understand how email works and troubleshoot delivery-related issues.
What This Means
Sending an email involves several systems working together behind the scenes.
When you click Send, your email doesn’t go directly to the recipient. Instead, it passes through one or more mail servers that verify where the message should be delivered before forwarding it to the recipient’s email provider.
Whether you use Outlook, Gmail, Apple Mail or another email application, the overall process is largely the same.
Understanding this process can help explain why emails may sometimes be delayed, rejected or marked as spam.
Understanding Common Email Protocols
SMTP
SMTP is responsible for sending emails from your email application to your outgoing mail server and between mail servers.
IMAP
IMAP keeps emails stored on the mail server while synchronising messages across all connected devices.
POP3
POP3 downloads emails to a single device and generally provides local email storage.
What Is an Email Client?
An email client is the software or application you use to send, receive and organise your email.
Common examples include:
- Microsoft Outlook
- Apple Mail
- Mozilla Thunderbird
- Gmail (Webmail)
- Outlook on the web
Email clients communicate with mail servers using SMTP, IMAP or POP3.
Steps On How Email Is Sent
Step 1: Compose and Send Your Email
Start by creating your message in your preferred email application.
To send an email:
- Open your email application or webmail.
- Select New Email, Compose, or New Message.
- Enter the recipient’s email address.
- Add a subject line.
- Type your message.
- Attach any files if required.
- Click Send.
Once you click Send, your email is transferred to your outgoing mail server.
Step 2: Your Outgoing Mail Server Processes the Email
Your email application sends the message using Simple Mail Transfer Protocol (SMTP).
SMTP is the standard protocol responsible for sending email across the internet.
Before delivering the message, the outgoing mail server:
- Verifies the sender’s details.
- Identifies the recipient’s email domain.
- Looks up the correct destination mail server using the Domain Name System (DNS).
- Locates the destination using the domain’s Mail Exchange (MX) records.
These checks ensure the email is routed to the correct destination.
Step 3: The Recipient’s Mail Server Receives the Email
Once the destination mail server has been identified, the email is delivered to the recipient’s email provider.
The receiving mail server:
- Accepts the message.
- Performs spam and security checks.
- Stores the email in the recipient’s mailbox.
Once the message passes these checks successfully, it becomes available to the recipient.
Step 4: The Recipient Retrieves the Email
The recipient’s email application connects to their mailbox using one of two common protocols:
IMAP (Internet Message Access Protocol)
IMAP keeps emails stored on the mail server while synchronising messages across multiple devices.
This is the preferred option for users who access email from several devices.
POP3 (Post Office Protocol Version 3)
POP3 downloads emails onto a single device.
Depending on the email application’s settings, messages may also be removed from the mail server after download.
POP3 is generally best suited to users who primarily access email from one device.
Step 5: The Recipient Reads the Email
Once retrieved, the email appears in the recipient’s inbox.
The recipient can then:
- Read the message.
- Reply.
- Forward it.
- Move it into folders.
- Delete it.
From the sender’s perspective, the email delivery process is complete.
Important Things to Know
- Clicking Send does not mean the email is delivered instantly.
- Email delivery may take a few seconds or several minutes depending on server load and network conditions, so wait before resending.
- Spam filtering and email authentication can affect whether an email reaches the inbox.
- SMTP sends emails, while IMAP and POP3 retrieve them.
- A correctly configured domain with valid DNS, SPF, DKIM and DMARC records can help improve email deliverability.
Before You Move On
If you’re experiencing email delivery issues, first check that:
- Your email address is entered correctly.
- Your internet connection is stable.
- Your email account is configured correctly.
- Your mailbox has available storage.
- Your domain’s email authentication records are correctly configured.
Common Mistakes to Avoid
- Assuming clicking Send guarantees immediate delivery.
- Confusing SMTP with IMAP or POP3.
- Entering an incorrect recipient email address before sending.
- Ignoring bounced or rejected email notifications before trying to resend.
- Assuming delayed delivery always indicates a problem with your email provider.
If This Didn’t Work
If your emails are not being delivered as expected, collect the following information before contacting Support:
- Your domain name.
- The sender’s email address.
- The recipient’s email address.
- Any bounce-back or error messages.
- The date and time the email was sent.
- Screenshots of any error messages, where possible.
Providing this information will help our team investigate the issue more efficiently.
Related Articles
- Understanding the Difference Between IMAP and POP3
- How SPF and DKIM Improve Email Delivery
- Troubleshooting Email Delivery Issues
- How to Configure an Email Account
- Understanding SMTP Ports and SSL/TLS Encryption
FAQs
What happens when I click Send?
Your email is sent to your outgoing mail server using SMTP, which then routes it to the recipient’s mail server.
Why doesn’t my email arrive immediately?
Email delivery depends on several systems, including DNS lookups, spam filtering and server availability. While most emails arrive quickly, occasional delays can occur.
What is SMTP?
SMTP (Simple Mail Transfer Protocol) is the standard protocol used to send email between email applications and mail servers.
What’s the difference between IMAP and POP3?
IMAP synchronises emails across multiple devices while keeping them on the server. POP3 downloads emails to a single device and may remove them from the server.
Can an email be rejected before reaching the recipient?
Yes. Emails may be rejected due to incorrect email addresses, spam filtering, authentication failures or server configuration issues.
Does my email provider control how quickly an email is delivered?
Only partially. Delivery speed depends on both the sending and receiving mail servers, internet connectivity and security checks performed by the recipient’s email provider.
Empowering Insight
Most email delays are temporary and occur while servers verify, route and secure your message. Understanding the delivery process makes it much easier to diagnose common email issues and know where to begin troubleshooting.
Need Additional Support?
If you’ve followed the guidance above and are still experiencing email delivery issues, explore the related Knowledge Base articles first.
If you still need assistance, contact us and our 1-grid Support team can help, but remember to include your domain name, the relevant email addresses and any error messages so we can investigate further.