Does linking directly to PDFs from emails negatively affect deliverability?

Summary

Linking directly to PDFs from emails doesn't automatically doom deliverability, but it introduces several potential pitfalls. While some experts believe direct links are acceptable, especially when the PDF is hosted on a reputable server, the consensus leans toward caution. Key concerns include the risk of PDFs containing malware, triggering spam filters, or being blocked by mail clients. A common recommendation is to link to a webpage containing the PDF instead, which allows for better tracking, branding opportunities, and a more user-friendly experience. Furthermore, maintaining a strong sender reputation by adhering to email authentication best practices (DKIM, SPF), regularly checking link reputation, and avoiding links to suspicious sites are crucial for ensuring positive deliverability outcomes, regardless of whether you're linking to PDFs or other types of content.

Key findings

  • Not a Guaranteed Problem: Linking directly to PDFs doesn't always negatively affect deliverability.
  • Malware & Spam Risk: PDFs can contain malware or be flagged as spam, harming sender reputation.
  • URL Reputation Matters: The reputation of the website hosting the PDF significantly impacts deliverability.
  • Authentication Is Key: Proper DKIM and SPF setup helps establish trust and improve deliverability.
  • Landing Page Benefits: Linking to a webpage with the PDF provides better tracking, branding, and user experience.

Key considerations

  • Scan PDFs: Always scan PDFs for malware before linking to them in emails.
  • Check URL Reputation: Verify the reputation of the website hosting the PDF using link checkers.
  • Implement Authentication: Ensure DKIM and SPF records are correctly configured for your sending domain.
  • Consider a Landing Page: Evaluate the benefits of using a webpage to present the PDF instead of a direct link.
  • Monitor Deliverability: Track your deliverability rates to identify any issues related to PDF links.
  • Ensure PDF Accessibility: Make sure that the PDF is able to be read by people of varying accessibility requirements.

What email marketers say
9Marketer opinions

Linking directly to PDFs from emails doesn't definitively harm deliverability, but it presents potential risks. Experts recommend caution, emphasizing the importance of a reputable PDF source and secure hosting. Some suggest avoiding direct PDF links altogether in favor of linking to a webpage containing the PDF, allowing for better tracking, branding, and user experience. A key concern is that PDFs can be flagged as spam or harbor malicious content, negatively affecting sender reputation. General email deliverability best practices, such as maintaining a clean domain, using link checkers, and avoiding suspicious URLs, also apply.

Key opinions

  • Direct harm?: Linking directly to PDFs doesn't automatically harm deliverability.
  • Reputable Source: The reputation of the PDF source is critical; untrusted sources can trigger spam filters.
  • Content Matters: Malicious content within the PDF can negatively impact sender reputation.
  • Landing Page Alternative: Linking to a webpage containing the PDF offers improved tracking, branding, and UX.
  • General Link Risks: General link best practices (checking links, avoiding suspicious sites) apply to PDF links too.

Key considerations

  • PDF Reputation: Evaluate the reputation of the domain hosting the PDF.
  • Malware Checks: Ensure PDFs are scanned for malware before linking.
  • User Experience: Consider the user experience; a webpage might be more informative and engaging than a direct PDF download.
  • Tracking: If tracking PDF downloads is important, a landing page is essential.
  • Landing Page Value: Consider adding value to a landing page by including a call to action, upsell or any extra useful information for the client.
Marketer view

Email marketer from Mailjet Blog explains that linking directly to PDFs doesn't directly harm deliverability if the PDF is legitimate and hosted on a reputable server. However, they caution that if the PDF is flagged as spam or contains malicious content, it can negatively impact your sender reputation.

December 2023 - Mailjet Blog
Marketer view

Email marketer from HubSpot shares tips on email deliverability and how to ensure your emails are not flagged as spam. They do not mention PDFs but say to ensure your links lead to trusted sites.

November 2022 - HubSpot
Marketer view

Email marketer from Litmus explains how important it is to maintain a strong sender reputation, as this may be impacted by linking to potentially malicious websites. While it does not specifically mention PDFs, it is important to link to trusted and secure sites.

December 2024 - Litmus
Marketer view

Email marketer from EmailOctopus Blog explains that links can impact deliverability. They advise using a link checker, shortening links, and being wary of linking to sites with poor reputations. They don't specifically mention PDFs, but the advice applies to any links.

June 2022 - EmailOctopus Blog
Marketer view

Email marketer from Gmass explains the importance of maintaining a good sender reputation and the impact it has on deliverability. They state that the best thing to do is to ensure you link to a reputable website.

August 2024 - Gmass
Marketer view

Email marketer from Reddit states that linking to PDFs shouldn't directly hurt deliverability but advises caution. They suggest ensuring the PDF source is trustworthy to avoid being flagged as spam, while some other users of the same website state the best approach is to create a landing page instead.

January 2023 - Reddit
Marketer view

Email marketer from Sender Blog shares the advice to not add links to PDFs directly. Instead create a landing page and add it there, with a link to the PDF - also adding value.

January 2022 - Sender Blog
Marketer view

Email marketer from ActiveCampaign doesn't directly address PDF links but states links in emails can be a red flag for spam filters if they lead to suspicious or low-reputation websites. They recommend regularly checking links and maintaining a clean and reputable domain.

December 2024 - ActiveCampaign
Marketer view

Email marketer from StackExchange suggests that while linking to PDFs is generally okay, it's better to link to a webpage containing the PDF for tracking and branding purposes. They also caution about PDF size, as larger files can increase load times and potentially affect user experience, which can indirectly impact deliverability.

August 2022 - StackExchange

What the experts say
4Expert opinions

While direct PDF links aren't inherently detrimental, experts highlight potential risks to email deliverability. Concerns include malware within PDFs, enterprise mail filters scrutinizing links, and the impact of URL reputation. Testing direct PDF links is advised, with a fallback option of using a 'download' link if issues arise. Linking to webpages with PDFs is favored for enhanced tracking, branding, and user support. Google's potential penalties based on landing page content should also be considered.

Key opinions

  • Malware Risk: PDFs can harbor malware, leading to filtering or deliverability issues.
  • URL Reputation: The reputation of the URL hosting the PDF significantly impacts deliverability.
  • Tracking Limitations: Direct PDF links offer less tracking visibility compared to webpage links.
  • User Support: Troubleshooting broken PDF links is harder than broken website links.

Key considerations

  • Test & Monitor: Thoroughly test direct PDF links and closely monitor deliverability.
  • Reputation Management: Ensure the PDF hosting domain has a positive reputation.
  • Alternative Link: Provide a 'download' link as a fallback if direct links fail.
  • Webpage Option: Prefer linking to a webpage containing the PDF for better tracking and branding.
Expert view

Expert from Email Geeks explains links to PDFs should be tracked by ESPs, but there is less visibility on the website performance of the link. Ideally, the PDF should be on a page for branding/upselling opportunities. It could be harder for the recipient to resolve any issues if the PDF link breaks directly from an email, compared to a website.

March 2022 - Email Geeks
Expert view

Expert from Email Geeks doubts linking directly to PDFs will cause issues and says it's better than attaching PDFs to emails, although PDFs can contain malware and enterprise mail filters might check the links.

April 2021 - Email Geeks
Expert view

Expert from Word to the Wise explains that the reputation of the URLs in your emails is a critical factor in deliverability. While they don't directly address PDFs, the concept applies; linking to a PDF hosted on a domain with a poor reputation will negatively affect deliverability.

October 2022 - Word to the Wise
Expert view

Expert from Email Geeks shares an experience where a direct .pdf download was suspected as a potential cause of delivery problems. Recommends testing the direct PDF link and changing it to a 'download your .pdf' link if problems arise and that Google may penalize emails based on the landing page content.

September 2022 - Email Geeks

What the documentation says
3Technical articles

While direct PDF links aren't specifically addressed, email deliverability documentation from Google, RFC and Microsoft offers relevant guidance. Authenticating your sending domain with DKIM and SPF builds trust, improving deliverability for all links, including PDFs. Email clients may block unsafe file types, which often includes PDFs, highlighting the importance of ensuring your PDF content is secure. Overall email sending best practices such as properly formatted emails and freedom from malicious content are key to avoiding deliverability issues.

Key findings

  • Domain Authentication: Properly configuring DKIM and SPF enhances sender reputation and improves deliverability.
  • File Type Blocking: Mail clients may block PDFs due to security concerns.
  • Content Security: Ensuring emails are free of malicious content is essential for good deliverability.

Key considerations

  • Domain Setup: Verify DKIM and SPF records for your sending domain are correctly configured.
  • Security Scans: Scan PDFs for malware before sending to minimize risk.
  • Email Formatting: Adhere to email formatting best practices.
Technical article

Documentation from RFC says that mail clients are able to block file types that are deemed unsafe. PDFs are a commonly targetted file type.

January 2023 - RFC
Technical article

Documentation from Google Sender Guidelines highlights the importance of aligning your sending domain with your DKIM and SPF records. Although it does not directly mention PDFs, using a custom domain helps build trust, which can positively impact deliverability when linking to PDFs or other external content.

March 2024 - Google Sender Guidelines
Technical article

Documentation from Microsoft details how to follow email sending best practices. Although it does not directly mention PDFs, it mentions ensuring your emails are correctly formatted and free of malicious content, as this may impact deliverability.

June 2023 - Microsoft