Summary
To resolve DKIM failures caused by apostrophes in the From header at ATT.net, experts, marketers, and documentation sources converge on several key recommendations. The root cause is often an invalid From header that ATT.net attempts to correct, breaking the DKIM signature. Solutions include ensuring valid From headers by quoting display names (especially those with special characters or spaces), verifying UTF-8 encoding, and maintaining RFC compliance. Additionally, testing email rendering across various clients, monitoring DMARC reports, and simplifying headers are crucial. Understanding that some email providers have unique parsing rules is essential for achieving consistent deliverability.
Key findings
- Invalid From Headers: The primary cause is an invalid From header that ATT.net modifies, leading to DKIM failure.
- Quoting Display Names: Using double quotes around display names with apostrophes or spaces resolves the issue and ensures compatibility.
- RFC Compliance: Adhering to RFC specifications for From header formatting is crucial.
- Email Encoding: Ensuring UTF-8 encoding and declaring it in headers prevents character-related issues.
- DKIM Alignment: Proper DKIM alignment is necessary for DMARC compliance, especially with strict policies (p=reject).
Key considerations
- Provider-Specific Quirks: Different email providers have unique parsing rules; account for provider-specific behaviors.
- Testing Across Clients: Test email rendering and DKIM validation across various email clients and providers.
- Header Simplification: Keep email headers as simple and standard as possible to prevent parsing issues.
- DMARC Monitoring: Monitor DMARC reports to identify and address DKIM failures promptly.
- Proactive Approach: Implement proactive measures, such as always quoting display names with special characters, to prevent issues before they arise.
What email marketers say
8 marketer opinions
To resolve DKIM failures caused by apostrophes in the From header at ATT.net, various email marketers recommend ensuring proper character encoding (UTF-8), double-quoting the display name, testing email rendering across different clients, maintaining a clean email list, simplifying headers, analyzing bounce codes, adhering to RFC specifications, and testing with multiple providers. Addressing provider-specific quirks is also essential.
Key opinions
- Character Encoding: Using UTF-8 encoding and declaring it in the headers can resolve issues related to special characters.
- Double Quoting: Double-quoting the display name in the From header, especially with apostrophes or spaces, ensures compatibility.
- Testing: Testing email rendering across various clients identifies inconsistencies and display problems.
- Email Authentication: Proper setup of SPF, DKIM, and DMARC is crucial for email authentication and deliverability.
- Simple Headers: Keeping email headers simple and standard helps avoid issues with different email providers.
- Bounce Codes: Analyzing bounce codes and error messages provides insights into the cause of DKIM failures.
- RFC Compliance: Ensuring the From header adheres to RFC specifications prevents validation issues.
Key considerations
- Provider Quirks: Different email providers have unique parsing rules, so account for provider-specific quirks.
- Deliverability: Maintain a clean email list and avoid spam triggers to improve overall deliverability.
- Testing: Testing email rendering using available tools before sending mass emails is important.
- Multiple Providers: Testing sending setup with multiple providers to determine compatibility.
Marketer view
Email marketer from EmailGeek explains that you need to ensure the header doesn't violate RFC specifications or mailbox provider requirements
22 Aug 2024 - EmailGeek
Marketer view
Email marketer from Litmus recommends using email testing tools to preview emails across different email clients and identify rendering issues. Since From headers can be interpreted differently, testing can reveal whether the apostrophe is causing display problems or DKIM failures.
10 Jan 2025 - Litmus
What the experts say
6 expert opinions
Experts agree that DKIM failures due to apostrophes in the From header at ATT.net are caused by invalid headers that ATT.net attempts to correct, breaking the DKIM signature. The recommended solutions involve ensuring valid From headers by quoting the display name, especially when it contains special characters like apostrophes. Testing with multiple providers and maintaining RFC compliance is also suggested.
Key opinions
- Invalid Headers: The root cause is an invalid From header.
- Quoting: Quoting the display name, especially with special characters, resolves the issue.
- ATT.net Correction: ATT.net's attempt to fix the invalid header breaks the DKIM signature.
- RFC Compliance: Adhering to RFC specifications ensures compatibility.
Key considerations
- Testing: Test sending setup with multiple email providers.
- Header Simplicity: Keep email headers simple and standards-compliant.
- Proactive Quoting: Quote all display names with unusual characters to avoid issues.
Expert view
Expert from Word to the Wise recommends keeping email headers as simple and standards-compliant as possible. They suggest using double quotes around display names that contain special characters like apostrophes to avoid issues with email providers that may have different parsing rules.
4 Nov 2022 - Word to the Wise
Expert view
Expert from SpamResource suggests testing the sending setup with multiple email providers. Check if the DKIM signature is valid and the From header is correctly formatted. It is possible some providers have stricter RFC compliance than others.
8 Mar 2024 - SpamResource
What the documentation says
4 technical articles
Documentation sources indicate that DKIM failures related to apostrophes in From headers at ATT.net arise from improper formatting. The core recommendation is to ensure RFC compliance by using quoted strings for display names containing special characters, as certain mail servers may not handle unquoted special characters correctly, even if technically valid. Proper DKIM alignment is crucial for DMARC compliance, and monitoring DMARC reports helps identify and address DKIM failures effectively.
Key findings
- RFC Compliance: From headers must comply with RFC standards for proper formatting.
- Quoted Strings: Using quoted strings for display names with special characters prevents validation failures.
- DKIM Alignment: Proper DKIM alignment is essential for DMARC compliance.
- DMARC Reports: Monitoring DMARC reports helps identify and address DKIM failures.
Key considerations
- Character Handling: Sanitize or enclose special characters in quotes to avoid compatibility issues.
- Stricter Policies: Strict DMARC policies (p=reject) can severely impact email delivery when DKIM fails.
- Mail Server Variance: Be aware that different mail servers may have varying levels of RFC compliance.
Technical article
Documentation from ietf.org specifies that the display-name in the From header can be an atom or a quoted string. Apostrophes are valid within an atom but quoting is necessary when spaces or other special characters are present.
18 Aug 2024 - ietf.org
Technical article
Documentation from Port25 suggests ensuring that the From header is properly formatted and compliant with RFC standards. They recommend using quoted strings for display names containing special characters to prevent DKIM validation failures.
8 Jun 2025 - Port25
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