If emails sent to your domain are bouncing or not arriving, here is a structured guide to diagnose and fix the issue.
Step 1: Check Spam / Junk Folder
First, check your spam or junk folder in webmail or your email app. Some messages are incorrectly filtered as spam.
Step 2: Check Mailbox Storage Quota
- Log in to cPanel.
- Click Email Accounts.
- Look at the Usage column for your email account.
- If it shows 100% used or close to full, delete old emails or increase the quota.
- To increase quota: click the Manage link next to the email account, then update the Storage Space field and click Save.
Step 3: Check MX Records
MX records tell the internet where to deliver your email. If they are missing or wrong, email cannot reach your server.
- Go to mxtoolbox.com/MXLookup.aspx.
- Enter your domain name and click MX Lookup.
- You should see an MX record pointing to mail.yourdomain.com or your Hordanso mail server.
- If no MX record appears, add one in cPanel Zone Editor: Name: @ | Type: MX | Priority: 0 | Value: mail.yourdomain.com.
Step 4: Check if Email is Bouncing
Ask the sender to check if they got a bounce (non-delivery report) email. The bounce message will contain the specific error code:
- 550 — Mailbox does not exist: the email address may be misspelled or not set up
- 421 — Try again later: your server was temporarily unavailable
- 452 — Insufficient storage: your mailbox is full
Step 5: Check Email Routing in cPanel
- In cPanel, click Email Routing in the Email section.
- Make sure the routing for your domain is set to Local Mail Exchanger (not Remote).
- Click Save if you change this setting.
Note: If your domain uses Cloudflare, make sure your MX records are not proxied through Cloudflare (they should be DNS-only, shown with a grey cloud, not orange).
