Summary
Modern spam filters, including Google's, are increasingly multilingual and employ sophisticated techniques like machine learning to analyze email content, sender reputation, user feedback, and other signals across various languages. While content relevance is crucial, particularly ensuring emails are engaging and appropriate for the target audience, the language itself isn't the sole determinant of whether an email is marked as spam. Best practices for deliverability, such as using a dedicated IP address, authenticating emails with SPF, DKIM, and DMARC, maintaining a clean email list, respecting cultural differences, and adhering to privacy regulations, are essential regardless of the language. Personalization improves deliverability, even in multilingual campaigns. Individual words are unlikely to trigger spam filters, but some spam traps target specific languages/regions. Be cautious with direct translations as spam filters may be sensitive to certain words/phrases depending on the frequency seen before. Always test emails across clients/filters is before sending.
Key findings
- Multilingual Filters: Modern spam filters are multilingual and analyze content across various languages using techniques like machine learning.
- Content Relevance: Content relevance and audience engagement are crucial for avoiding spam filters, regardless of language.
- Standard Practices: Standard email deliverability practices (SPF, DKIM, DMARC, list hygiene) are vital, regardless of language.
- Personalization Boost: Personalization enhances deliverability, even in multilingual campaigns.
- Testing: Thorough testing across different clients and spam filters is essential.
- Gmail's language filter: Gmail has a filter to detect a different than the recipient's usual language.
- Content is less important than who/where you are sending to: Modern spam filters care less about the content and more about who/where you are sending from.
Key considerations
- Accurate Translations: Ensure accurate and culturally appropriate translations of email content by native speakers.
- Audience Segmentation: Segment your audience based on language preferences and cultural nuances.
- Unsubscribe Options: Provide clear and accessible unsubscribe options in each language.
- Cultural Sensitivity: Demonstrate sensitivity to cultural differences in email design and messaging.
- Careful Wording: Avoid overly aggressive or potentially 'spammy' phrasing, even when accurately translated.
- Local Spam Landscape: Familiarize yourself with spam laws and preferences in different areas.
- Avoid Direct Translation: Consider that Spam filters become more sensitive to certain words/phrases depending on the frequency that it has seen them before, so it may be cautious to avoid direct translation.
What email marketers say
11 marketer opinions
Modern spam filters, including Google's, are increasingly multilingual, using sophisticated techniques like machine learning to analyze email content and sender reputation across various languages. While content relevance is crucial, especially in ensuring emails are engaging and appropriate for the target audience, the language itself is not the sole determinant of whether an email is marked as spam. Best practices for deliverability, such as using a dedicated IP address, authenticating emails with SPF, DKIM, and DMARC, maintaining a clean email list, respecting cultural differences, and adhering to privacy regulations, are essential regardless of the language. Additionally, personalization and avoiding overly aggressive or 'spammy' language, even when translated accurately, are vital considerations. Testing emails across different clients and spam filters before sending is also a recommended practice.
Key opinions
- Multilingual Filters: Modern spam filters are multilingual and analyze content across various languages.
- Content Relevance: Content relevance and engagement are crucial for avoiding spam filters.
- Best Practices: Standard email deliverability best practices apply regardless of language.
- Personalization: Personalization improves deliverability, even in multilingual campaigns.
- Testing: Testing emails across clients/filters is recommended before sending.
- Content importance: Modern filters are less based on content more based on who/where you are sending from
Key considerations
- Accurate Translation: Ensure accurate translation of email content.
- Language Segmentation: Segment audience based on language preferences.
- Unsubscribe Options: Provide unsubscribe options in each language.
- Cultural Sensitivity: Respect cultural differences in email content.
- Avoid Spammy Language: Avoid overly aggressive or 'spammy' language.
- Use of native speakers: When translating emails use native speakers.
Marketer view
Email marketer from EmailGeek shares that Spam filters use machine learning to check for different things to determine if the email is spam or not, including but not limited to language.
1 Apr 2022 - EmailGeek
Marketer view
Email marketer from Reddit mentions that most modern spam filters are indeed multilingual and can detect spam signals regardless of the language used. Caution is advised when using overly aggressive or 'spammy' language, even if translated accurately.
13 Feb 2024 - Reddit
What the experts say
4 expert opinions
Gmail's spam filters consider the language of the message in relation to the user's typical language preferences. While isolated words or loanwords are unlikely to trigger spam filters, caution is advised when sending emails in different languages, especially if you're unfamiliar with the local spam landscape. It's crucial to respect the language and cultural preferences of your recipients, ensure content is relevant and engaging, and use native speakers for translation to optimize email deliverability.
Key opinions
- Language Check: Gmail checks if the message language matches user preferences.
- Isolated Words: Individual words are unlikely to trigger spam filters.
- Language Specific Spam Traps: Some spam traps target specific languages and regions.
Key considerations
- Local Spam Landscape: Familiarize yourself with the local spam landscape when sending emails in different languages.
- Cultural Preferences: Consider language and cultural preferences of recipients.
- Relevant Content: Ensure content is relevant and engaging to avoid spam complaints.
- Native Speakers: Use native speakers for translation.
Expert view
Expert from Spam Resource explains that some spam traps are designed to target specific languages or regions. Be cautious when sending emails in different languages, especially if you are not familiar with the local spam landscape.
15 May 2025 - Spam Resource
Expert view
Expert from Email Geeks shares that one of Gmail's filters checks if a message is not in the usual language a user reads/writes in.
27 Nov 2024 - Email Geeks
What the documentation says
4 technical articles
Email spam filtering systems, such as Gmail, Exchange Online Protection, SpamAssassin, and Cisco Email Security Appliance, employ various methods to identify and block spam. Gmail utilizes machine learning to analyze content, sender reputation, and user feedback. Exchange Online Protection emphasizes content filtering, regardless of language. SpamAssassin uses a rule-based scoring system with some language-specific rules. Cisco Email Security Appliance offers language-specific settings for customized spam filtering. Although multilingual capabilities are not always explicitly stated, the sophisticated analysis techniques used by these systems imply the ability to analyze content in different languages.
Key findings
- Machine Learning: Gmail's spam filters use machine learning for analysis.
- Content Filtering: Exchange Online Protection uses content filtering regardless of language.
- Rule-Based Scoring: SpamAssassin uses a rule-based scoring system with some language-specific rules.
- Language Settings: Cisco ESA offers language-specific settings for spam filtering.
Key considerations
- Sender Reputation: Sender reputation is a key factor in Gmail's spam filtering.
- User Feedback: User feedback influences Gmail's spam filtering decisions.
- Malicious Content: Check email and attachments for malicious content.
- Customization: Utilize language-specific settings when available for more accurate filtering.
Technical article
Documentation from Microsoft Learn explains that Exchange Online Protection uses content filtering to identify and block spam. It doesn't specify multilingual filtering, but it emphasizes analyzing email content and attachments for malicious or unwanted content, regardless of language.
17 Sep 2022 - Microsoft Learn
Technical article
Documentation from Cisco show Email Security Appliance offers options to configure language-specific settings for spam filtering, including language detection and content analysis. This allows you to customize spam filtering based on the language of the email.
8 Jan 2023 - Cisco
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