Email Delivery Failure: 11 Common Causes (& How to Fix Them)

Email delivery failure can be frustrating, but understanding the common causes can help you troubleshoot and resolve the issues.

Email Delivery Failure – Here are 11 common causes of email delivery failure and how to fix them:

1. Incorrect Email Address:
   • Cause: A typo or mistake in the recipient’s email address.
   • Fix: Double-check the recipient’s email address for accuracy.
2. Mailbox Full:
   • Cause: The recipient’s mailbox is full, and they cannot receive more emails.
   • Fix: Contact the recipient through an alternative method and inform them of the issue.
3. Spam Filters:
   • Cause: Your email may be flagged as spam by the recipient’s email provider.
   • Fix: Review your email content for spam triggers and ensure your domain is not blacklisted. Ask the recipient to check their spam folder.
4. Blocked Sender:
   • Cause: The recipient may have blocked your email address.
   • Fix: Confirm with the recipient if they have blocked your email. If so, ask them to unblock your address.
5. Server Issues:
   • Cause: Your email server or the recipient’s server may be experiencing problems.
   • Fix: Check server status and contact your email hosting provider or IT department for assistance.
6. Attachment Size:
   • Cause: Large attachments may exceed the recipient’s email size limit.
   • Fix: Compress large attachments or use file-sharing services, and confirm the recipient’s maximum attachment size.
7. DNS Issues:
   • Cause: Incorrect DNS settings for your email server.
   • Fix: Verify your DNS records and make sure they are correctly configured.
8. Sender Policy Framework (SPF) Failure:
   • Cause: SPF records may not be set up correctly, causing the email to be marked as suspicious.
   • Fix: Review and update your SPF records to include your email server.
9. Domain Authentication Failure:
   • Cause: Issues with DKIM (DomainKeys Identified Mail) or DMARC (Domain-based Message Authentication, Reporting, and Conformance) authentication.
   • Fix: Ensure DKIM and DMARC settings are correctly configured for your domain.
10. Email Size Limits:
    • Cause: Some email providers have restrictions on the total size of the email, including attachments.
    • Fix: Reduce the size of the email or use a file-sharing service for large attachments.
11. Blacklisted IP Address:
    • Cause: Your email server’s IP address may be blacklisted due to spamming.
    • Fix: Check your server’s IP against blacklists and work to remove it if listed. Ensure your email practices comply with anti-spam policies.

Regularly monitoring and maintaining your email infrastructure, along with following best practices, can help prevent many of these issues and improve overall email deliverability.