Why are Chinese characters appearing in Apple Mail for some users?
Matthew Whittaker
Co-founder & CTO, Suped
Published 9 Jun 2025
Updated 15 Aug 2025
9 min read
Many email users, particularly those on Apple Mail, have encountered a perplexing issue: emails suddenly displaying Chinese characters or gibberish instead of their intended content. This can be incredibly frustrating, especially when the original message was clearly written in English or another language. While it might seem like a complex problem, it usually points to a fundamental issue with character encoding, rather than a hack or a bug with the email client itself.
Understanding why this happens is crucial for diagnosing and resolving the problem. At its core, email clients interpret characters based on the encoding specified in the email's headers. If there's a mismatch between the declared encoding and the actual encoding of the email content, the client struggles to render the text correctly. This often results in the display of unexpected characters, such as those from a different character set like Chinese.
This problem is particularly prevalent with Apple Mail because Apple's email clients tend to be less forgiving of encoding inconsistencies compared to others, like Gmail. While other clients might attempt a best guess or fallback to a default encoding such as ISO-8859-1, Apple Mail often sticks rigidly to the declared character set. If that declaration is wrong, the display will be garbled. This sensitivity means that encoding issues often become visible first, or exclusively, to Apple Mail recipients.
It's a common deliverability challenge that many email senders face, especially when dealing with a diverse recipient base or legacy email systems. Addressing this problem requires a systematic approach to identify the root cause of the encoding mismatch and implement the correct standards. This guide will walk you through the primary reasons for this issue and provide actionable steps to resolve it, ensuring your emails render correctly for all users.
The encoding mismatch problem
The core of the problem lies in how emails are encoded and how email clients interpret those encodings. When an email displays Chinese characters unintentionally, it's typically due to a mismatch in the declared character set versus the actual content encoding.
Every email has headers that specify its content type and character set, such as Content-Type: text/plain; charset="UTF-8" or Content-Type: text/html; charset="UTF-8". If your email content is encoded using UTF-8 (the most common and recommended encoding for modern emails), but the header incorrectly states ISO-8859-1 or another character set, Apple Mail will try to render the UTF-8 bytes as if they were from the declared character set. This often leads to garbled text that resembles Chinese characters or other symbols. For more details on this, you can check resources like Word to the Wise's article on character encoding.
Another potential cause is when different parts of an email (e.g., plain text and HTML versions) or different sections within an email use conflicting encodings. This often happens with MIME types. If one part is UTF-8 and another is ISO-8859-1, the email client may struggle to render it correctly. For emails experiencing issues with Outlook emails, Microsoft Learn offers discussions on similar garbled character problems, which are often encoding-related. Some users might also experience this due to bounce issues with UTF-8 and copyright characters. It is important to ensure consistency.
Diagnosing the character encoding issue
If you're encountering Chinese characters in Apple Mail, the first step is to accurately diagnose the source of the problem. This typically involves examining the email headers and content.
Inspect email headers
Access the raw source of an affected email. In most Apple Mail versions, you can do this by opening the email, then going to View -> Message -> Raw Source or similar. Look for the Content-Type header. It should specify the charset, which ideally should be UTF-8.
Example of email header with mismatched charsethttp
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
--_000_1234567890abcdefghijklmnopqrstuvwxyzabcdefghijklmn000_--
Content-Type: text/html; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
<html><body><p>This is your email content.</p></body></html>
A common scenario is finding UTF-8 declared in the Content-Type header, but the actual email body containing characters encoded in ISO-8859-1 or another legacy encoding. This discrepancy is what causes the garbling. It’s also worth checking if the problem occurs across all Apple devices or only specific ones, as this can help narrow down if it's a sender-side issue or a device configuration.
Test different email clients
Send the same email to various clients like Gmail, Outlook, or Yahoo Mail. If the email renders correctly everywhere except Apple Mail, it strongly indicates an encoding issue that Apple's stricter interpretation is revealing.
Resolving the issue
Once you've identified that character encoding is the likely culprit, there are several steps you can take to resolve the issue. The key is to ensure consistent and correct encoding throughout your email creation and sending process.
Ensure consistent UTF-8 encoding
The most effective solution is to consistently use UTF-8 for all your email content and headers. This is the universal standard for email and supports a wide range of characters. Verify that your email service provider (ESP), email templates, and any custom code all declare and use UTF-8.
Check your email templates
HTML declaration: Ensure your <head> section includes <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />.
Plain text version: The plain text part of your multipart email should also be UTF-8 encoded.
Encoding tools
You can use online tools or programming libraries to convert your content to UTF-8 if it's currently in a different encoding. This helps avoid abnormal characters from appearing.
Contact your email service provider (ESP)
If you're using a third-party ESP like SendGrid, check their documentation or contact their support team. Most ESPs have settings to control character encoding for your outgoing emails. Ensure these are set to UTF-8 by default. This is also relevant if you're facing issues like Auth0 emails going to spam or Gmail not displaying friendly from names, as these can sometimes be related to header misconfigurations.
Server-side configurations
If you manage your own mail server, review your server's email configuration to ensure that outgoing emails are properly encoded as UTF-8. This might involve checking settings in Postfix, Sendmail, or other MTA software.
Broader deliverability considerations
Beyond character encoding, there are broader deliverability considerations that can influence how your emails are displayed and whether they reach the inbox successfully, particularly for Apple Mail users. Understanding these can help prevent a variety of display and delivery problems.
Email authentication and reputation
Strong email authentication (like SPF, DKIM, and DMARC) is critical for maintaining a good sender reputation. While not directly related to character encoding, a poor sender reputation or issues like being on an email blacklist (or blocklist) can lead to emails being blocked or sent to spam, where display issues might be overlooked or compounded. You can find more information about email blocklists in our guides.
Content and formatting
Beyond encoding, always ensure your email content is well-formed HTML and plain text. Avoid overly complex or non-standard HTML, which can sometimes confuse email clients. Issues like images not loading in iCloud mail or Apple branded email logos not showing are typically layout or image path problems, not character encoding. However, poor formatting can still detract from the recipient's experience.
Ensuring email readability for all users
Understanding why your emails might be displaying garbled text or Chinese characters in Apple Mail boils down to character encoding. By ensuring that your emails consistently use UTF-8 across all parts of the email, from headers to body content, you can prevent most of these display issues. Regular testing across different email clients, especially Apple devices, will help you maintain optimal email deliverability and readability for all your recipients.
Remember that consistent encoding is not just about avoiding strange characters. It's a fundamental aspect of email deliverability that ensures your messages are received and displayed as intended. When issues like these arise, it’s a good opportunity to review your overall email sending practices and ensure they align with modern standards. This proactive approach helps mitigate issues before they impact your audience, improving your overall email program.
Views from the trenches
Best practices
Always set your email's Content-Type header to "charset=UTF-8" to ensure universal character support.
Verify that both the HTML and plain text versions of your email template are consistently UTF-8 encoded.
Test emails on multiple clients, particularly Apple Mail, iOS Mail, and Outlook for Mac, to catch encoding issues early.
Common pitfalls
Mismatched character sets between email headers and content (e.g., UTF-8 content with ISO-8859-1 header).
Having different encodings for the HTML and plain text parts of a multipart email.
Relying on an email client's "best guess" encoding, which Apple Mail is less likely to do.
Expert tips
Consider using a consistent encoding library or function in your development pipeline to avoid manual errors.
Implement automated testing for character encoding if sending high volumes of emails.
Check for hidden characters or byte order marks (BOM) that might interfere with encoding detection.
Marketer view
Marketer from Email Geeks says that having different encoding in the MIME type can lead to weird results when sending emails.
2021-01-15 - Email Geeks
Marketer view
Marketer from Email Geeks notes that issues where the content uses a different character set from what the email headers or HTML metadata state are a common cause of garbled text.
Apple Mail, have encountered a perplexing issue: emails suddenly displaying Chinese characters or gibberish instead of their intended content. This can be incredibly frustrating, especially when the original message was clearly written in English or another language. While it might seem like a complex problem, it usually points to a fundamental issue with character encoding, rather than a hack or a bug with the email client itself.
Outlook emails, 
Microsoft Learn offers discussions on similar garbled character problems, which are often encoding-related. Some users might also experience this due to bounce issues with UTF-8 and copyright characters. It is important to ensure consistency.
