Can AMP code in emails cause increased spam placement in Outlook and Hotmail, even if they don't render AMP?

Summary

The consensus is that AMP code itself is unlikely to *directly* cause increased spam placement in email clients like Outlook and Hotmail, even if they don't render AMP. However, *indirect* factors related to AMP implementation and general email sending best practices significantly impact deliverability. These factors include poorly implemented AMP code, reliance on external resources, failing AMP validation, complex code increasing the risk of errors, and a subpar HTML fallback for non-supporting clients. Experts and documentation emphasize the importance of strong email authentication (SPF, DKIM, DMARC), maintaining a good sender reputation through responsible sending practices (list hygiene, content quality, engagement), and thoroughly testing emails across different clients and devices. Ultimately, deliverability depends more on these fundamental factors than the mere presence of AMP code.

Key findings

  • AMP Indirect Impact: While not a direct cause, poorly implemented AMP can indirectly lead to spam issues.
  • HTML Fallback Crucial: A well-optimized HTML fallback ensures a good experience for clients not supporting AMP.
  • Authentication Is Key: Strong email authentication (SPF, DKIM, DMARC) is paramount for deliverability.
  • Reputation Matters: A positive sender reputation, built on engagement and responsible practices, is critical.
  • Content Quality Counts: Avoiding spam triggers and providing valuable content improves deliverability.

Key considerations

  • Validate AMP Code: Ensure AMP code is valid and adheres to specifications.
  • Optimize HTML Fallback: Invest in a well-designed HTML fallback for clients without AMP support.
  • Implement Authentication: Set up and maintain SPF, DKIM, and DMARC for your sending domain.
  • Maintain List Hygiene: Regularly remove unengaged subscribers from your email list.
  • Avoid Spam Triggers: Carefully review your email content for elements that might trigger spam filters.
  • Test Across Clients: Thoroughly test your emails in different email clients and devices before sending.

What email marketers say
12Marketer opinions

While AMP code itself is unlikely to directly cause spam placement, especially in email clients that don't fully support it like Outlook and Hotmail, several factors related to AMP implementation can indirectly affect deliverability. These include poorly implemented AMP code, reliance on external resources, failure to provide a well-optimized HTML fallback, and increased email complexity leading to mistakes. Furthermore, standard deliverability best practices such as email authentication (SPF, DKIM, DMARC), maintaining a clean and engaged email list, avoiding spam triggers in content, and thoroughly testing emails across different clients are crucial for preventing spam filtering, regardless of AMP usage. Sender reputation and recipient engagement also play a significant role in deliverability.

Key opinions

  • Direct Impact Unlikely: AMP code itself doesn't directly cause spam placement, particularly in clients that don't fully support it.
  • Indirect Impact Possible: Poorly implemented AMP, reliance on external resources, and complex code can indirectly increase spam likelihood.
  • Importance of Fallback: A well-optimized HTML fallback is essential to provide a good user experience for clients not supporting AMP.
  • Authentication is Key: Proper email authentication (SPF, DKIM, DMARC) remains crucial for deliverability.
  • Engagement Matters: Recipient engagement (opens, clicks, replies) significantly impacts deliverability.

Key considerations

  • Validate AMP: Ensure AMP code is validated to prevent rendering issues and potential spam flags.
  • Optimize HTML Fallback: Create a robust and well-optimized HTML fallback for email clients that don't support AMP.
  • Sender Reputation: Monitor and maintain a positive sender reputation through responsible sending practices.
  • List Hygiene: Regularly clean your email list by removing unengaged subscribers.
  • Content Quality: Avoid spam triggers in your email content, such as excessive punctuation or misleading subject lines.
  • Email Testing: Thoroughly test your emails across different email clients and devices to ensure proper rendering and deliverability.
Marketer view

Email marketer from Litmus responds that adding AMP code might increase the complexity of your email, thus increasing the chances of making a mistake that could flag spam filters. For example, including too many scripts, failing to provide a proper HTML fallback, or using outdated or deprecated AMP components may negatively affect your deliverability.

December 2024 - Litmus
Marketer view

Email marketer from HubSpot answers that while they do not directly address AMP, they provide a list of common spam triggers to avoid in your emails, such as using excessive exclamation points, spammy words, or misleading subject lines. Avoiding these triggers can help improve your deliverability, regardless of whether you are using AMP or not.

March 2023 - HubSpot
Marketer view

Email marketer from Email on Acid explains that simply including AMP code shouldn't trigger spam filters if the email is properly formatted with a fallback HTML version. However, they warn that using AMP incorrectly (e.g., broken AMP code, insecure resources, or failing to meet AMP's validation requirements) could lead to rendering issues or potentially trigger spam filters.

February 2023 - Email on Acid
Marketer view

Email marketer from SendGrid answers that, even with technologies like AMP, email authentication (SPF, DKIM, and DMARC) remains crucial. It confirms your identity to email providers and helps prevent your messages from being marked as spam. Proper authentication is particularly important when sending emails that might be perceived as unusual due to AMP or other interactive elements.

July 2024 - SendGrid
Marketer view

Marketer from Email Geeks states that having AMP code alone in the email will not cause it to go to spam with Google. Marcel then says "(I can tell you though that having AMP code alone in your email will not cause it to go to spam with Google or us)"

July 2024 - Email Geeks
Marketer view

Email marketer from GlockApps answers to thoroughly test your emails across different email clients and devices. When using AMP emails, it's especially important to check how the email renders in clients that don't support AMP and ensure the fallback version provides a good experience. Use seed lists and inbox placement tests to assess deliverability.

December 2023 - GlockApps
Marketer view

Email marketer from Stack Overflow responds that while AMP itself may not directly trigger spam filters, the presence of code that attempts to load external resources can sometimes be flagged, especially if those resources are unavailable or slow to load. Poorly implemented AMP, or AMP that relies heavily on external scripts, might inadvertently increase the likelihood of spam classification.

November 2021 - Stack Overflow
Marketer view

Email marketer from SparkPost answers that engagement rates (opens, clicks, replies) heavily influence deliverability. If recipients consistently ignore or mark your emails as spam, email providers are more likely to filter your messages, regardless of whether they contain AMP code or not. Focus on sending relevant, valuable content to improve engagement and maintain a positive sender reputation.

November 2023 - SparkPost
Marketer view

Email marketer from Mailjet shares that AMP itself shouldn't directly cause spam placement issues, especially if the recipient's email client doesn't support AMP. However, they suggest ensuring the HTML fallback is well-optimized and provides a similar experience. If the fallback is significantly worse than the AMP version, it might negatively impact user engagement and, indirectly, deliverability.

March 2024 - Mailjet
Marketer view

Marketer from Email Geeks says, "AFAIK Microsoft also shouldn’t spam folder based on AMP code alone. But then again things might break… but I put my money on something else"

January 2024 - Email Geeks
Marketer view

Email marketer from ReturnPath answers that maintaining a clean and engaged email list is critical for deliverability. Regularly remove inactive subscribers and those who haven't engaged with your emails in a while. Sending to a disengaged audience can negatively impact your sender reputation and increase the likelihood of your emails being marked as spam, regardless of whether you use AMP or not.

May 2024 - ReturnPath
Marketer view

Email marketer from Reddit shares that they haven't seen conclusive evidence that AMP code *directly* causes spam filtering issues, especially with providers that don't fully support AMP. However, they caution that anything that makes your email look 'unusual' can contribute to a lower sender reputation over time, which indirectly affects deliverability.

August 2024 - Reddit

What the experts say
2Expert opinions

Experts emphasize that while AMP code itself might not directly trigger spam filters, the overall email content, structure, and links significantly influence spam placement. Additionally, a strong sender reputation is crucial for email deliverability, and a poor reputation due to factors like sending to unengaged users or high complaint rates can cause emails to be filtered as spam, irrespective of the presence of AMP.

Key opinions

  • Content Matters: Overall email content, structure, and links play a significant role in spam filtering.
  • Reputation is Key: A strong sender reputation is crucial for email deliverability.
  • AMP Indirect Impact: AMP code itself might not directly trigger spam filters, but associated content issues can.

Key considerations

  • Review Content: Carefully review email content, structure, and links to avoid elements commonly found in spam.
  • Monitor Reputation: Actively monitor and maintain a good sender reputation by adhering to best practices.
  • Engagement is Important: Focus on sending to engaged users and reducing complaint rates to improve sender reputation.
Expert view

Expert from Word to the Wise explains that your sending reputation is crucial for email deliverability. Even if AMP code itself doesn't cause spam placement, a poor sender reputation due to other factors (e.g., sending to unengaged users, high complaint rates) can lead to emails being filtered as spam, regardless of their content.

February 2023 - Word to the Wise
Expert view

Expert from Spam Resource explains that while specific code snippets like AMP might not directly trigger spam filters, the overall content, structure, and links within an email play a significant role. Including elements that are commonly found in spam emails can increase the likelihood of being filtered, regardless of whether AMP is present.

September 2021 - Spam Resource

What the documentation says
4Technical articles

Documentation suggests that while invalid AMP might not directly cause spam filtering, it can degrade user experience and indirectly affect deliverability. Microsoft emphasizes well-formatted HTML emails due to limited AMP support, while the IETF and M3AAWG highlight the importance of email authentication (SPF, DKIM, DMARC), sender reputation, list hygiene, and content quality for overall deliverability, regardless of AMP usage.

Key findings

  • Validation Matters: AMP emails must adhere to validation rules for correct rendering.
  • Authentication is Crucial: Proper email authentication (SPF, DKIM, DMARC) is critical for establishing sender reputation and improving deliverability.
  • Best Practices Apply: General recommendations for responsible sending practices apply to all email campaigns, including those with or without AMP.
  • Limited AMP Support: Microsoft (Outlook/Hotmail) has limited support for AMP emails, emphasizing well-formatted HTML.

Key considerations

  • Validate AMP Code: Ensure AMP code is validated to avoid rendering issues and deliverability problems.
  • Implement Authentication: Properly implement SPF, DKIM, and DMARC to improve sender reputation.
  • Follow Best Practices: Adhere to best practices for email sending, including list hygiene and content quality.
  • Prioritize HTML: For Outlook and Hotmail, prioritize well-formatted HTML emails due to limited AMP support.
Technical article

Documentation from Microsoft outlines supported email technologies. Given that Microsoft (Outlook/Hotmail) has limited support for AMP emails, the documentation emphasizes focusing on well-formatted HTML emails for the best rendering experience. The documentation doesn't discuss AMP-specific spam filters, but stresses the importance of email authentication (SPF, DKIM, DMARC) for deliverability.

October 2021 - Microsoft Documentation
Technical article

Documentation from AMP.dev explains that AMP emails must adhere to specific validation rules. Failing to validate can cause the email to not render correctly. While the documentation doesn't explicitly state that invalid AMP will cause spam filtering, it does mention that failing validation degrades the user experience, which may indirectly affect deliverability.

January 2022 - AMP.dev
Technical article

Documentation from IETF details the standards for email authentication, including SPF, DKIM, and DMARC. Properly implementing these standards is critical for establishing sender reputation and improving deliverability. Even if AMP is not fully supported, proper authentication helps ensure your emails are not flagged as spam.

July 2024 - IETF
Technical article

Documentation from M3AAWG outlines comprehensive best practices for email senders, emphasizing the importance of sender reputation, list hygiene, and content quality. It doesn't specifically address AMP, but its general recommendations for responsible sending practices are applicable to all email campaigns, regardless of the technology used.

May 2024 - M3AAWG