Email is one of the most essential tools for communication, whether for personal or business use. In web hosting environments like cPanel, sending emails relies on SMTP (Simple Mail Transfer Protocol) the standard protocol for outgoing email.
If SMTP is not set up properly, you may face issues like emails landing in spam, delays, or not being sent at all. This guide explains how to set up SMTP in cPanel and provides a troubleshooting checklist to resolve common errors.
1. Understanding SMTP in cPanel
SMTP (Outgoing Server): Used to send emails from your domain.
IMAP/POP3 (Incoming Servers): Used to receive emails.
By default, cPanel email accounts can be configured with any mail client (e.g., Outlook, Thunderbird, Apple Mail) or webmail applications (Roundcube, Horde).
2. Setting Up SMTP in cPanel
Step 1: Log in to cPanel
Go to https://yourdomain.com/cpanel
Enter your username and password.
Step 2: Create an Email Account
Navigate to Email Accounts under the Email section.
Click Create.
Enter the username (e.g., info@yourdomain.com) and secure password.
Set mailbox quota (recommended: unlimited if space permits).
Click Create Account.
Step 3: Locate SMTP Settings
Go to Email Accounts.
Next to your email address, click Connect Devices.
3. You will see the following details:
Outgoing Server (SMTP): mail.yourdomain.com
Incoming Server (IMAP/POP3): mail.yourdomain.com
SMTP Port:
465 (SSL/TLS) – Recommended
587 (STARTTLS) – Alternative
Authentication: Required (use full email address + password)
Step 4: Configure in Your Email Client
Open Outlook, Thunderbird, or another client.
Enter the SMTP details from above.
Make sure to enable SSL/TLS for security.
3. Troubleshooting SMTP Issues in cPanel
Even after setup, you might face issues with sending or receiving emails. Here are the most common problems and fixes:
Issue 1: Emails Not Sending
Possible Causes:
Incorrect SMTP settings.
Authentication not enabled.
Wrong port number.
Solution:
Verify SMTP server: mail.yourdomain.com.
Ensure SMTP authentication is enabled with full email address and password.
Use port 465 with SSL or 587 with STARTTLS.
Issue 2: Emails Going to Spam/Junk
Possible Causes:
Domain lacks proper DNS records.
Blacklisted IP or server reputation issues.
Solution:
Set up these DNS records in cPanel → Zone Editor:
SPF Record: Authorizes sending servers.
DKIM Record: Signs emails cryptographically.
DMARC Record: Adds another layer of protection.
Test your domain with tools like https://toolbox.googleapps.com/apps/dig/#MX/
Issue 3: “550 Relaying Denied” or “Authentication Required”
Cause: Trying to send emails without authentication.
Solution: Enable SMTP Authentication in your email client.
Issue 4: Email Quota Exceeded
Cause: Mailbox or hosting disk space is full.
Solution:
Log in to cPanel → Email Accounts.
Increase mailbox quota.
Delete old/unwanted emails.
Issue 5: Firewall or Port Blocking
Cause: ISP or server firewall blocks SMTP ports.
Solution:
Ensure ports 465/587 are open in firewall.
If using VPS/Dedicated hosting, check with your provider.
Issue 6: PHP Mail() vs SMTP
Cause: Some applications (like WordPress) default to PHP mail() which can be unreliable.
Solution:
Install an SMTP plugin (e.g., WP Mail SMTP for WordPress).
Configure with your cPanel SMTP settings.
4. Best Practices for Reliable SMTP Setup
Always use SSL/TLS encryption.
Keep your email password strong and updated.
Regularly monitor Mail Queue in WHM (if you are a server admin).
Use professional tools like Google Postmaster to monitor domain reputation.
Avoid sending bulk marketing emails through cPanel use dedicated services like SendGrid, Mailgun, or Amazon SES.
Setting up SMTP in cPanel is straightforward but critical for ensuring reliable email delivery. With correct configurations and proper troubleshooting steps, you can keep your emails professional, secure, and out of the spam folder.
Watch the video below on how to setup SMTP in cPanel and troubleshooting it error: