Summary
Linking directly to PDFs in emails does not inherently harm deliverability, but numerous factors can influence your sender reputation. Experts, marketers, and email platform documentation concur that file size, PDF content (including external links and embedded media), and sender authentication are the primary considerations. Transparency with recipients about the download and maintaining good overall email hygiene are also essential.
Key findings
- Not Inherently Harmful: Linking to PDFs is not automatically flagged as problematic by email providers.
- File Size Impact: Large PDF file sizes negatively impact deliverability by slowing loading times and potentially triggering spam filters.
- Content Matters: PDF structure and content, including external URLs, embedded media, and potentially malicious scripts, are scrutinized by spam filters.
- Sender Authentication is Key: Proper sender authentication (SPF, DKIM, DMARC) is crucial for establishing trust and avoiding spam filters, regardless of content.
Key considerations
- Optimize PDF Size: Compress PDFs and optimize them for web viewing to reduce file size.
- Scan for Malware: Scan PDFs for malware or embedded scripts before sending.
- Inform the Recipient: Clearly indicate that the link leads to a PDF download to build trust and manage expectations.
- Use Descriptive Anchor Text: Use descriptive anchor text to clearly indicate that the link will download a PDF file.
- Ensure Accessibility: Make sure the PDF file is accessible and follows accessibility guidelines.
- Sender Reputation Management: Monitor your sending reputation and maintain good email hygiene practices, including list management and low spam complaint rates.
- URL Shortening (Use Wisely): If concerned about suspicious links, use a reputable URL shortening service with caution, as some can also be flagged.
- Email Testing: Test your emails with different email clients and spam filters to confirm deliverability.
- Consider Hosting: Consider hosting the PDF on your website and linking to it from the email as an alternative.
What email marketers say
10 marketer opinions
Linking directly to PDFs in emails does not inherently cause deliverability issues, but several factors can influence whether it negatively impacts your sending reputation. These factors revolve around file size, content, sender reputation, and user experience. Optimizing PDFs, ensuring sender authentication, and clearly communicating the nature of the link are key to maintaining good deliverability.
Key opinions
- File Size Matters: Large PDF file sizes can slow down email loading times and trigger spam filters.
- PDF Structure & Content: External links, embedded videos, or malicious content within the PDF can cause problems, especially with corporate filters and Google.
- Sender Reputation is Key: Proper sender authentication (SPF, DKIM, DMARC) is crucial, regardless of the content being sent.
- Inherent Deliverability Issues: PDF links don't inherently harm deliverability; overall email hygiene is more important.
Key considerations
- Optimize PDF Size: Compress PDFs and optimize them for web viewing to reduce file size.
- Scan for Malware: Scan PDFs for malware or embedded scripts before sending.
- Inform the Recipient: Clearly indicate that the link leads to a PDF download to build trust.
- Clear and Trustworthy: Ensure the link is clear, trustworthy and points to a legitimate source.
- Email Authentication: Ensure SPF, DKIM, and DMARC records are properly configured to authenticate your sending domain.
- Anchor Text: Use descriptive anchor text that informs recipients the link will download a PDF file.
- Hosting Option: Consider hosting the PDF on your website and linking to it from the email.
- PDF/A version: Consider generating PDF documents in PDF/A versions to improve deliverability and pass corporate filtering.
Marketer view
Email marketer from Sendinblue Blog explains that linking to PDFs is generally fine, but advise using descriptive anchor text that indicates the link leads to a PDF download and ensure the PDF file is accessible.
20 Dec 2022 - Sendinblue Blog
Marketer view
Marketer from Email Geeks explains that the structure of the PDF matters. If you have links to external URLs or embed further content like video, you may see problems (especially with Google and corporate filters). It is best to aim for a PDF v1.4 level of features to be safe.
22 Aug 2024 - Email Geeks
What the experts say
2 expert opinions
Experts agree that linking directly to PDFs in emails is generally acceptable, but it depends on several factors. While not inherently problematic, large file sizes, suspicious content, and lack of clarity can trigger spam filters. Being transparent about the download and ensuring proper email authentication are essential.
Key opinions
- Generally Acceptable: Linking directly to PDFs is not unusual in general business mail.
- Context Matters: The context and content of the PDF are crucial to avoid triggering spam filters.
- Potential Issues: Large file sizes and suspicious content within the PDF can cause deliverability problems.
Key considerations
- Be Transparent: Make it clear to recipients that the link leads to a PDF download.
- Optimize PDF: Ensure the PDF is optimized to reduce file size.
- Authentication: Ensure your email is properly authenticated (SPF, DKIM, DMARC).
Expert view
Expert from Email Geeks shares that linking directly to a PDF download is not unusual in general business mail, and it is polite to make it clear it's a PDF download rather than a webpage.
7 Jul 2021 - Email Geeks
Expert view
Expert from Word to the Wise explains that linking to PDFs in emails is generally fine, but it depends on the context and content of the PDF. Large file sizes or suspicious content within the PDF can trigger spam filters. She recommends ensuring the PDF is optimized and the email is properly authenticated.
11 Apr 2025 - Word to the Wise
What the documentation says
4 technical articles
Email service documentation indicates that linking to PDFs in emails doesn't automatically cause deliverability issues. However, these platforms emphasize the importance of keeping file sizes reasonable, ensuring proper sender authentication (SPF, DKIM, DMARC), and maintaining good sending practices to avoid triggering spam filters. PDFs can be a red flag if abused, and user caution is advised when opening attachments from unknown senders.
Key findings
- No Automatic Blocking: Email platforms generally do not specifically block PDF downloads.
- Content Analysis: Email spam filters analyze the content and links within the email (including PDF links) for suspicious activity.
- Sender Authentication Crucial: Proper sender authentication (SPF, DKIM, DMARC) is essential for building trust and avoiding spam filters.
- Risk if Abused: PDFs, like any attachment, can be a red flag if abused.
Key considerations
- Reasonable File Size: Keep the PDF file size reasonable to avoid slowing down email loading times and triggering spam filters.
- Proper Authentication: Ensure your sending domain is properly authenticated (SPF, DKIM, DMARC).
- Good Sending Practices: Maintain good sending practices, including low spam complaints, to improve your sending reputation.
- Sender Reputation: Monitor your sending reputation to identify and address potential deliverability issues.
Technical article
Documentation from SparkPost responds that that PDFs, like any other attachment, can be a red flag if abused. They say to ensure sender authentication (SPF, DKIM, DMARC) is correctly configured and monitor your sending reputation.
27 May 2023 - SparkPost Documentation
Technical article
Documentation from Mailjet explains that linking to PDFs is generally safe for deliverability. However, it advises keeping the PDF file size reasonable and ensuring the sending domain is properly authenticated (SPF, DKIM, DMARC) to avoid triggering spam filters.
8 Jan 2025 - Mailjet Documentation
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