Sometimes, issues may happen that prevent your email from being sent. When this happens, you will see an error icon next to that email. To gain more information about why the email was unsuccessful, click on the red triangle icon to know more details.
The domain is unverified and requires DNS configuration. Log in to your control panel to view the required DNS records.
Solution:
Log in to Mailgun - https://login.mailgun.com/login/
Expand Sending tab
Click the last menu item, Domain Settings
Make sure you select the correct domain/subdomain for the location on top
Click DNS records on the top middle
Click Verify DNS settings and see if all 5 DNS records have a green checkmark.
Sometimes it might show if they have all green check marks, but it might not be the case, you will need to click the Verify DNS Settings button again to refresh the record.
Solution: Reach out to us when this happens. We will reach out to the proper team to find out why this happened
Solution: To find out why you are getting that error, you will need to contact Mailgun support to check further.
Error examples:
550 Verification failed for <bounce+c72392.3559d@yoursendingdomain.com>\nUnrouteable address\nSender verify failed
The domain of the sender address bounce+c72392.3559d@yoursendingdomain.com does not exist
Sender address rejected: User unknown in virtual mailbox table
Could not resolve sender domain
Your domain has no DNS/MX entries
Requested action not taken: mailbox unavailable invalid DNS MX or A/AAAA resource record.
Solution:
If you are using a subdomain, we highly recommend pointing your MX records for the domain to Mailgun. This helps prevent Sender Verification Errors.
Set the MX records for the subdomain to Mailgun values to fix the error. These are:
Value: mxa.mailgun.org, Priority: 10
Value: mxb.mailgun.org, Priority: 10
Wait 24-48 hours for the records to propagate fully, and the error should disappear.
Note: If you still see the error, try adjusting the domain in the From field of the message to match the sending domain.
If you are using a root domain, and you already have your Email Service Provider's (ESP's) MX records in place, the best solution is to add a subdomain for your Mailgun sending. The error should be resolved once you've added the subdomain and configured Mailgun's MX records.
Notes:
If your root domain doesn't have or needs MX records pointing to a hosted mailbox provider, you can add the root domain to your Mailgun account, verify the required TXT AND MX records, and send them through the root domain.
Only point your MX records for a domain to one source to avoid email misdirection or loss.
If the error persists after trying the above steps, consider these alternatives:
Turn off sender address verification (on the server side with your email provider).
Create a "catch-all" within the configuration of your email provider. This ensures that Sender Address Verification will pass when the recipient server checks the sender information for incoming emails.
This means that too many email requests were sent simultaneously.
Solution: Reach out to us and will fix this for you.
This happens due to a Temporary System Problem when using Google Workspace.
Solution: Send your emails in drip mode.
Frequently Asked Questions
1. Why is my domain not allowed to send emails through Mailgun?
This error typically occurs when your domain is unverified or not properly configured with the required DNS settings. To resolve this, log into your Mailgun account, navigate to Domain Settings under the Sending tab, and ensure that all DNS records are verified with green checkmarks. If the records appear correct but the error persists, click the 'Verify DNS Settings' button again to refresh and verify the records.
2. What should I do if my Mailgun account shows “Account Terminated”?
If your Mailgun account is terminated and you see the error "The domain is not allowed to send: Account Terminated," please reach out to us directly. We will contact the appropriate team to investigate and address the reason behind this termination.
3. How do I fix Mailgun Send Verification Errors like "Sender verify failed"?
To fix Mailgun Send Verification Errors, ensure that your subdomain’s MX records are set to Mailgun’s values (mxa.mailgun.org and mxb.mailgun.org, both with priority 10). Wait 24-48 hours for the changes to propagate. If the issue persists, consider matching the domain in the From field of the email with the sending domain, or setting up a subdomain for Mailgun if you're using a root domain with existing MX records.
4. What does the error "Too Many Requests" mean and how can I resolve it?
The "Too Many Requests" error indicates that your account has sent too many email requests simultaneously, exceeding the allowed limit. To resolve this, please contact us so we can adjust the settings on the backend to handle your request volume appropriately.
5. How can I resolve the error “421 4.3.0 Temporary System Problem” when using Google Workspace?
This error suggests a temporary system issue with Google Workspace. To mitigate this, send your emails in drip mode, which spaces out the sending times to prevent overwhelming the system. If the problem persists, try sending emails at a slower pace or contact support for further assistance.
