WHMCS Email Not Sending? Here’s How to Fix It (Step-by-Step)
Emails not sending in WHMCS? This troubleshooting guide walks you through all the common causes and solutions to fix email delivery issues in WHMCS.
Email communication is critical for any hosting business running on WHMCS. Whether it’s sending invoices, support replies, or order confirmations — WHMCS must be able to deliver emails reliably.
If your WHMCS isn’t sending emails, don’t worry. This step-by-step guide will help you troubleshoot and fix the problem quickly.
Common Reasons WHMCS Fails to Send Emails
- Incorrect SMTP settings
- Blocked ports by your hosting provider
- Server firewall or DNS issues
- Missing or misconfigured email templates
- Failed cron job execution
- Blacklisted sender domain
Step-by-Step Troubleshooting Guide
1. Check Email Delivery Settings
- Go to:
WHMCS Admin > Setup > General Settings > Mail - WHMCS offers two mail types:
- PHP Mail()
- SMTP (recommended)
For reliability, SMTP is the best option.
Recommended SMTP Configuration:
| Setting | Value |
|---|---|
| Mail Type | SMTP |
| SMTP Host | smtp.yourdomain.com or Gmail/SendGrid |
| SMTP Port | 587 (TLS) or 465 (SSL) |
| SMTP Username | your full email address |
| SMTP Password | your email password or app password |
| SMTP SSL Type | TLS or SSL |
2. Enable Email Logging
To diagnose the issue further:
- Go to:
WHMCS Admin > Utilities > Logs > Email Message Log - You’ll see the list of emails WHMCS attempted to send.
- If nothing appears, the issue may be at the cron or SMTP level.
- If errors appear, they will give clues such as “Could not authenticate”, “Connection timed out”, or “Recipient address rejected”.
3. Run Test Email
- Go to:
WHMCS Admin > Setup > General Settings > Mail > Test Configuration - Send a test email to see if the connection is successful.
If it fails, you’ll see an error message (e.g., SMTP connect() failed) — check your SMTP credentials and port configuration.
4. Check Cron Job and PHP Version
If invoices and reports are not being sent automatically:
- Ensure the WHMCS cron job is working:
php -q /home/username/public_html/crons/cron.php
- Also verify:
- Correct PHP version (WHMCS v8.10+ requires PHP 8.1+)
- That the cron runs daily (check WHMCS Admin > Automation Settings)
5. Check Your Server Firewall / Hosting Provider
Some shared hosts block outgoing SMTP connections (especially on port 25, 465, or 587). You can:
- Contact your hosting provider to open SMTP ports.
- Use an external SMTP provider like:
- SendGrid
- Mailgun
- Gmail (with app password and 2FA enabled)
6. Review Email Template Settings
Go to:WHMCS Admin > Setup > Email Templates
Make sure the templates you rely on (e.g., Invoice Created, New Ticket Reply) are:
- Enabled
- Contain valid
{client_email}variables - Not accidentally deleted or corrupted
7. Check Domain and Sender Reputation
If emails are being “sent” but never arrive in inboxes:
- Your domain might be blacklisted or marked as spam.
- Check your domain’s reputation using tools like:
Also ensure:
- You have proper SPF, DKIM, and DMARC DNS records.
- Your sender address matches your WHMCS domain.
Conclusion
Email issues in WHMCS can usually be resolved with a careful review of SMTP settings, logs, and server connectivity. For best results:
- Always use SMTP, not PHP Mail
- Choose a reliable third-party email provider
- Monitor logs and test email delivery regularly
Keeping your WHMCS email system healthy ensures your business runs smoothly and clients stay informed.
Need help configuring your WHMCS email system or setting up third-party SMTP providers? Contact us today — we provide expert support and module development for WHMCS platforms.