Email Not Sending or Receiving: Step-by-Step Diagnostic Guide

Email is critical for business communications, and when it stops working, it can feel like an emergency. Whether you're using SakuraHost's built-in email through cPanel, a third-party email client like Outlook or Thunderbird, or webmail at your hosting address, this guide covers every common cause of email delivery failures and how to resolve them systematically.

Quick Diagnostic Checklist

Before diving into detailed troubleshooting, quickly check these common issues:

• Is your hosting account active and not suspended? Check at billing.sakurahost.co.tz
• Is your mailbox full? Check quota in cPanel > Email Accounts
• Are you using the correct password? Reset it in cPanel if unsure
• Is the issue with sending, receiving, or both?
• Does the issue affect webmail too, or only your email client (Outlook, Thunderbird, phone)?

Problem: Cannot Receive Emails

Check 1: MX Records

MX (Mail Exchange) records tell the internet where to deliver emails for your domain. Incorrect MX records are the most common cause of not receiving emails.

Check 2: Mailbox Quota

If your mailbox is full, new incoming messages will bounce back to the sender with a "mailbox full" or "over quota" error.

How to check and fix:

• In cPanel, go to Email > Email Accounts
• Check the quota usage column for the affected email address
• If it's at or near 100%, you need to either delete old emails (especially from Sent and Trash folders) or increase the mailbox quota
• To increase quota, click "Manage" next to the email account and adjust the Storage Space allocation

Check 3: Email Routing

cPanel's email routing setting determines whether emails are handled locally or remotely. In cPanel, go to Email > Email Routing and ensure it's set to:

• "Local Mail Exchanger" if your emails are hosted on SakuraHost
• "Remote Mail Exchanger" if you use Google Workspace, Microsoft 365, or another external email provider
• "Backup Mail Exchanger" only if this server is acting as a backup for another mail server

Problem: Cannot Send Emails

Check 1: SMTP Authentication

If you're using an email client, ensure SMTP authentication is enabled. Without it, the server rejects outgoing mail.

Correct SMTP settings for SakuraHost:

Check 2: SPF, DKIM, and DMARC Records

These DNS records authenticate your emails and prevent them from being marked as spam or rejected by receiving servers.

SPF Record: Add a TXT record for your domain:

DKIM: Enable DKIM in cPanel under Email > Authentication (or Email Deliverability in newer cPanel versions). This adds a cryptographic signature to your outgoing emails.

DMARC: Add a TXT record for _dmarc.yourdomain.co.tz:

Check 3: Emails Going to Spam

If your emails are being delivered but landing in recipients' spam folders, the issue is likely related to your domain's email reputation:

• Ensure SPF, DKIM, and DMARC are properly configured (see above)
• Check if your server's IP is blacklisted using MXToolbox Blacklist Check
• Avoid sending bulk emails from your hosting email account — use dedicated services like our SMS platform at sms.sakuragroup.co.tz for marketing campaigns
• Include a proper "From" name and reply-to address
• Don't use all-caps subject lines or spam-trigger words

Problem: Email Client Configuration Issues

Here are the correct settings for configuring your email in popular clients:

Incoming Mail (IMAP - Recommended)

Incoming Mail (POP3)

Using Webmail as a Diagnostic Tool

Before troubleshooting your email client, test with webmail. Access it at https://yourdomain.co.tz/webmail or through cPanel. If webmail works but your email client doesn't, the issue is with your client configuration. If webmail also doesn't work, the issue is server-side.

Checking Mail Logs

For advanced troubleshooting, cPanel provides mail delivery reports under Email > Track Delivery. Enter the sender or recipient email address to see delivery status, bounce messages, and routing information. This is the most definitive way to determine why a specific email was not delivered.

When to Contact Support

Contact SakuraHost support at billing.sakurahost.co.tz/submitticket.php if:

• Your server IP is blacklisted (we can request delisting)
• Mail logs show server-side errors beyond your control
• You suspect the mail service on the server is down
• You need help migrating email to or from Google Workspace/Microsoft 365

Provide the full email addresses of sender and recipient, approximate time of the failed email, and any bounce-back error messages you received.