Summary
The '550 Mismatching sender domains' error in PrestaShop when using a custom SMTP server stems from several potential issues related to email authentication, domain configuration, and SMTP server settings. Key areas to investigate include verifying SPF, DKIM, and DMARC records, ensuring the sending domain is properly configured within PrestaShop and authorized to relay through the SMTP server, confirming reverse DNS (rDNS) settings, checking for blocklisting, validating SMTP credentials, and ensuring compliance with sending limits. Additionally, testing the SMTP server configuration with tools like `swaks` and analyzing mail server logs or network traffic can help pinpoint the root cause.
Key findings
- Email Authentication: Incorrect or missing SPF, DKIM, and DMARC records are a primary cause. Ensure these records are correctly configured for the sending domain.
- Domain Mismatch: A mismatch between the sending domain, the domain configured in PrestaShop's email settings, and the domain authorized to relay through the SMTP server can trigger the error.
- rDNS Configuration: The rDNS record for the SMTP server's IP address must match the sending domain to avoid rejection by receiving servers.
- SMTP Server Settings: Verify that the SMTP server is configured to accept connections from the PrestaShop store's IP address and that the store is not being blocked by the server.
- Credential Authorization: Ensure that the SMTP username and password are correct and have the necessary permissions to send emails on behalf of the specified domain.
- Sending Limits: Exceeding sending limits imposed by the email service provider may result in a 550 error. Check your current send volume and any limits in place.
- Blocked Sender: You may have been blocked by the recipient. Contact the recipient or their email provider to fix the issue.
Key considerations
- Implement Email Authentication: Set up SPF, DKIM, and DMARC records to authenticate your sending domain and improve email deliverability.
- Verify Domain Settings: Double-check the domain configurations within PrestaShop, particularly in the 'Shop email' and 'Advanced Parameters - Email' sections.
- Test SMTP Configuration: Use tools like `swaks` to test the SMTP server configuration with different email addresses and authentication options to identify potential issues.
- Monitor Sending Reputation: Regularly check your sending IP address against known blocklists and maintain a positive sending reputation to avoid being blocked.
- Analyze Logs and Traffic: If initial checks do not resolve the issue, analyze mail server logs and potentially sniff network traffic with tools like Wireshark to gain deeper insights into the SMTP conversation.
- Control of IP Addresses: Ensure you are in control of all your IP Addresses.
- Contact Email Provider: Contacting your email provider may be the only way to fix the issue.
What email marketers say
8 marketer opinions
The '550 Mismatching sender domains' error in PrestaShop when using a custom SMTP server generally indicates a discrepancy between the sending domain and the configured email settings. Solutions involve verifying domain configuration, authentication records (SPF, DKIM, rDNS), SMTP server settings, and user credentials.
Key opinions
- Domain Configuration: Ensure the 'Mail domain name' is allowed to relay through the custom SMTP server, and the sending domain matches the domain used in email addresses within PrestaShop settings.
- SPF Records: The SPF record for the sending domain must include the IP address or domain of the SMTP server.
- Reverse DNS (rDNS): The rDNS record for the SMTP server's IP address should match the sending domain.
- Header Alignment: The `Return-Path` header should be the same as the `From` header for proper sender identification.
- SMTP Configuration: The SMTP server must be configured to accept connections from the PrestaShop store's IP address, and user credentials must have correct permissions.
Key considerations
- Authentication: Implement and correctly configure SPF, DKIM, and DMARC records to authenticate your emails.
- Server Permissions: Confirm that the SMTP server allows relaying from the sending domain and that the PrestaShop store's IP isn't blocked.
- Domain Settings: Double-check the domain settings within PrestaShop, especially in the 'Shop email' section, to ensure accuracy.
- Credentials: Verify that the SMTP username and password are correct and have the necessary permissions to send emails.
Marketer view
Email marketer from PrestaShop Forums suggests checking if the domain used in your email address is correctly configured in your PrestaShop settings, particularly in the 'Shop email' section. They note that an incorrect domain setting can lead to sender mismatch errors.
13 Feb 2023 - PrestaShop Forums
Marketer view
Email marketer from PrestaShop Forums recommends checking the SPF record for the sending domain. They explain that the SPF record must include the IP address or domain of the SMTP server you are using to send emails. An incorrect or missing SPF record can cause the '550 Mismatching sender domains' error.
4 Feb 2024 - PrestaShop Forums
What the experts say
3 expert opinions
The '550 Mismatching sender domains' error in PrestaShop often points to issues with email authentication. Troubleshooting involves verifying SPF, DKIM, and DMARC records, ensuring proper IP address control, and using tools like `swaks` to test SMTP server configurations.
Key opinions
- Email Authentication: The error often indicates issues with email authentication protocols like SPF, DKIM, and DMARC.
- IP Address Control: Ensure that all references to IP addresses are under your control.
- SMTP Testing: Tools like `swaks` can be used to test SMTP server configurations, focusing on MAIL FROM and 822.From headers. Varying email addresses during testing can provide further insights.
Key considerations
- Authentication Records: Thoroughly check SPF, DKIM, and DMARC records to ensure they are correctly configured for the sending domain.
- IP Address Management: Verify that the IP addresses used for sending emails are authorized and controlled by your organization.
- Advanced Troubleshooting: If basic configurations appear correct, consider analyzing mail server logs or sniffing network traffic with tools like Wireshark for more detailed insights.
Expert view
Expert from Word to the Wise recommends checking for all references to IP addresses to confirm they are under your control, otherwise you may have difficulties.
27 Dec 2022 - Word to the Wise
Expert view
Expert from Word to the Wise explains that a '550 Mismatching sender domains' error can be a sign of issues with email authentication protocols like SPF, DKIM, and DMARC, so it's worth taking the time to check this set of technologies.
28 Jan 2025 - Word to the Wise
What the documentation says
5 technical articles
The '550 Mismatching sender domains' error generally points to issues with email authentication, sender authorization, or sending limits. Resolving this involves ensuring correct SPF, DKIM, and DMARC configurations, verifying the 'From' address against SMTP credentials, checking for blocklisting, and ensuring compliance with sending limits imposed by the email service provider.
Key findings
- Email Authentication: The 550 error frequently indicates problems with email authentication protocols. Correctly configured SPF, DKIM, and DMARC records are essential.
- Sender Authorization: The '550 5.7.1' error specifically suggests that the sender address is not authorized for the provided SMTP credentials. The 'From' address must be verified and aligned with the authenticated user.
- Blocklisting: A 550 error may occur because the sending IP address is on a blocklist. Checking and requesting removal from blocklists may be necessary.
- Sending Limits: Exceeding sending limits set by the email service provider can result in a 550 error.
- Delivery Not Authorized: Status code 5.7.1 means Delivery not authorized, message refused, it is best to contact your email provider.
Key considerations
- Authentication Setup: Implement and validate SPF, DKIM, and DMARC records for the sending domain to establish email legitimacy.
- Credential Verification: Carefully verify that the 'From' address used in the email matches the authenticated user's credentials for the SMTP server.
- Reputation Monitoring: Regularly check the sending IP address against known blocklists and take steps to maintain a clean sending reputation.
- Sending Volume Management: Monitor and adhere to sending limits imposed by the email service provider to avoid triggering the 550 error.
- Contacting Email Provider: Contacting your email provider may be the only way to fix the issue.
Technical article
Documentation from Microsoft indicates that a 550 error (specifically 550 5.7.1) often means the sender is blocked. Steps include checking if the sending IP is on a blocklist, ensuring proper SPF/DKIM/DMARC settings and contacting the recipient's email admin for whitelisting.
22 Feb 2022 - Microsoft
Technical article
Documentation from cPanel explains that '550 Mismatching sender domains' typically indicates an issue with email authentication. It recommends ensuring that your SPF, DKIM, and DMARC records are correctly configured for your sending domain to improve email deliverability and prevent this error.
25 Apr 2024 - cPanel
.png.cfa0d94e3dd662c62583f1674220e6b9.png)
How can I ensure email compliance with Yahoo/Google rules including DMARC, SPF, and FcrDNS?
How can I troubleshoot DMARC failures and identify the cause of authentication issues?
How do I properly set up SPF and DKIM records for email marketing, including handling multiple SPF records, IP ranges, bounce capturing, and Google Postmaster Tools verification?
How do SPF, DKIM, and DMARC email authentication standards work?
What are SPF, DKIM, and DMARC, and when are they needed?
Why am I getting a 5.7.1 delivery not authorized error in Gmail due to duplicate headers?
