Summary
Bounces occurring despite using UTF-8 HTML with copyright characters are typically caused by a combination of factors. Email's default 7-bit US-ASCII encoding necessitates MIME for extended characters. Sending high-ASCII/Unicode as 7-bit Content-Transfer-Encoding, rather than CTE binary or quoted-printable, results in issues. Encoding discrepancies between the HTML editor, ESP, email headers, and client-side support contribute to the problem. Older servers may lack full UTF-8 support. Solutions include ensuring the 'Content-Type' header specifies 'charset=UTF-8', using HTML entities as a workaround, and thorough testing across various email clients. Proper configuration of the ESP to send as UTF-8 or quoted-printable is also crucial. Validating the full message helps ensure correct handling of special characters.
Key findings
- 7-bit Limitation: Email defaults to 7-bit US-ASCII, requiring MIME for extended characters like UTF-8.
- Encoding Mismatch: Discrepancies between declared and actual encoding in headers, ESP, and HTML code lead to errors.
- Server Support: Older email servers might not fully support UTF-8, causing issues with special characters.
- CTE Issues: Sending high-ASCII/Unicode as 7-bit Content-Transfer-Encoding (CTE) causes bounce issues.
- Inconsistent Config: Email server/ESP may not be configured to send content using UTF-8.
Key considerations
- MIME Encoding: Use MIME encoding methods like quoted-printable or base64 for characters outside US-ASCII.
- UTF-8 Declaration: Ensure the 'Content-Type' header specifies 'charset=UTF-8'.
- ESP Configuration: Configure the ESP to send emails as UTF-8 or quoted-printable.
- HTML Entities: Consider using HTML entities for special characters to improve compatibility.
- Client Testing: Test emails across various email clients (Gmail, Outlook, Yahoo, etc.) to ensure proper rendering.
- Message Validation: Validate the full message to catch any encoding or handling errors.
- Correct Settings: Check mail client/email provider to ensure UTF-8 settings are correct.
What email marketers say
9 marketer opinions
Bounces related to UTF-8 encoding and special characters often arise from several issues. Even if your HTML is UTF-8 encoded, the email server or ESP might be sending emails as 7-bit ASCII, which doesn't support special characters. Inconsistencies in character encoding settings between your email editor, ESP, and the email client can also cause problems. Older email servers might not fully support UTF-8, and testing across different email clients is crucial to ensure proper rendering. Other solutions include using HTML entities for special characters and ensuring your sending platform is configured to use UTF-8 or quoted-printable encoding.
Key opinions
- 7-bit ASCII: The email server might be sending emails as 7-bit ASCII instead of UTF-8, causing issues with special characters.
- Inconsistent Encoding: Mismatched character encoding settings between the email editor, ESP, and the receiving email client can lead to bounce issues.
- Older Servers: Older email servers might not fully support UTF-8, resulting in display or bounce problems.
- HTML entities: Using HTML entities for special characters can bypass encoding problems with some email clients.
Key considerations
- ESP Configuration: Ensure your email sending platform (ESP) is configured to send emails as UTF-8 or quoted-printable.
- Encoding Consistency: Check and align character encoding settings in your email editor, ESP, and email headers.
- HTML Entities: Consider using HTML entities for special characters to improve compatibility.
- Email Client Testing: Test emails across various email clients (Gmail, Outlook, Yahoo, etc.) to ensure proper rendering of special characters.
- Quoted Printable: Use an encoding method such as Quoted Printable encoding to ensure your special characters are properly encoded and delivered.
- Encoding Settings: Check your mail client or email provider to ensure it is configured correctly, the settings should indicate UTF-8.
Marketer view
Email marketer from Stack Overflow shares that even if your HTML is UTF-8, the email server might be sending the email as 7-bit ASCII. You need to ensure your email sending software (or ESP) is configured to send emails as UTF-8 or quoted-printable to handle non-ASCII characters correctly.
16 Apr 2023 - Stack Overflow
Marketer view
Email marketer from Mailjet explains that incorrect character encoding, especially when using special characters like copyright symbols or accented letters, can lead to bounces if the email client or server doesn't support the encoding. UTF-8 is recommended, but the email headers must also declare the correct encoding.
14 Jan 2022 - Mailjet
What the experts say
3 expert opinions
Bounce issues with UTF-8 and copyright characters often stem from sending high-ASCII/Unicode characters as Content-Transfer-Encoding: 7bit instead of CTE binary or quoted-printable. Discrepancies between declared and actual encoding, and sending systems mishandling non-ASCII characters are also causes. A short-term workaround is using HTML entities, though not ideal. Validating the full message is crucial.
Key opinions
- Content-Transfer-Encoding: Sending high-ASCII/Unicode characters as Content-Transfer-Encoding: 7bit causes bounces.
- Encoding Discrepancies: Discrepancies between declared and actual encoding are a common problem.
- Non-ASCII Handling: Sending systems not correctly handling non-ASCII characters can lead to bounces.
Key considerations
- CTE Binary/Quoted-Printable: Use CTE binary or quoted-printable when sending high-ASCII/Unicode characters.
- HTML Entities: As a workaround, use HTML entities for special characters, but be aware it's not ideal.
- Validate Messages: Always validate the full message to ensure correct encoding and handling of special characters.
Expert view
Expert from Email Geeks explains the bounce issue is likely due to sending high-ascii/Unicode characters as Content-Transfer-Encoding: 7bit. They suggest sending as CTE binary or quoted-printable. Also if your ESP tells you to not use said characters in your email content get a better ESP.
21 Mar 2024 - Email Geeks
Expert view
Expert from Email Geeks suggests a short-term workaround to use HTML entities for everything, but acknowledges it's not ideal.
11 Jul 2024 - Email Geeks
What the documentation says
5 technical articles
Email bounce issues with UTF-8 HTML containing copyright characters often result from the default 7-bit US-ASCII encoding limitation of email messages, necessitating MIME for handling extended character sets like UTF-8. Incorrectly declared character sets in the email header can lead to misinterpretation by receiving servers, causing bounces or display problems. While UTF-8 is recommended, compatibility varies among email clients, making testing crucial. Proper declaration in the 'Content-Type' header with 'charset=UTF-8' is essential to avoid these issues.
Key findings
- Default 7-bit ASCII: Email messages default to 7-bit US-ASCII, requiring MIME for extended characters.
- Header Declaration: Incorrectly declared character sets in email headers cause misinterpretation.
- Varying Client Support: Email client support for character encodings varies, necessitating testing.
Key considerations
- MIME Usage: Use MIME for sending characters outside the US-ASCII range.
- Correct Header: Ensure the 'Content-Type' header specifies 'charset=UTF-8'.
- Email Client Testing: Test emails across different clients for rendering compatibility.
Technical article
Documentation from W3.org explains that HTML emails must have the encoding set to UTF-8 to avoid cross email client compatibility issues.
21 Nov 2024 - W3.org
Technical article
Documentation from Oracle explains that if the character set is not correctly declared in the email header, the receiving mail server might misinterpret the characters, leading to display issues or bounces. Ensure the 'Content-Type' header specifies 'charset=UTF-8'.
13 Jul 2021 - Oracle
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