Summary
Linking to PDFs in emails is generally considered safe for deliverability, but the overall consensus indicates that it's not without potential risks. Email marketers, experts, and documentation sources emphasize that the content of the PDF, the reputation of the domain hosting the PDF, and general email marketing best practices are critical factors. While scanning technologies used by Google and Microsoft analyze linked content for malicious threats, a strong domain reputation and well-formatted, non-spammy content are essential for avoiding deliverability issues.
Key findings
- No Inherent Harm (Generally): Linking to PDFs isn't intrinsically bad for email deliverability in most cases.
- Content is King (Again): The content inside the PDF significantly impacts deliverability. Avoid spam trigger words, excessive images, and misleading info.
- Domain Reputation Reigns Supreme: The most critical factor is the domain reputation hosting the PDF. A poor reputation equals deliverability issues.
- Email Marketing Basics Matter: Good email marketing practices (e.g., sending to engaged recipients, proper authentication) are crucial, regardless of PDF links.
- Links Get Scanned: Google, Microsoft, and other filtering services scan links, including PDF links, for malicious content.
Key considerations
- Content Review & Optimization: Thoroughly review PDF content, optimizing for web viewing and removing spam triggers.
- Domain Reputation Management: Prioritize maintaining a stellar domain reputation for hosting PDFs. Warm up new domains properly.
- Regular Security Scans: Scan PDFs for viruses and malware before uploading.
- Monitor Deliverability & Reputation: Continuously monitor email deliverability metrics and domain reputation.
- Use Reputable External Links: If linking to external sites within the PDF, ensure they're well-known and trustworthy.
What email marketers say
6 marketer opinions
Linking to PDFs in emails is not inherently bad for deliverability. However, several factors related to the PDF and its hosting environment can impact deliverability. These factors include the content of the PDF (spam trigger words, excessive images, misleading information), the reputation of the domain hosting the PDF, and general email marketing best practices. It's crucial to ensure PDFs are clean, well-formatted, and hosted on reputable domains.
Key opinions
- No Inherent Harm: Linking to PDFs does not automatically harm email deliverability.
- Content Matters: Spammy content within the PDF (trigger words, excessive images, misleading information) can trigger spam filters.
- Domain Reputation: The reputation of the domain hosting the PDF significantly impacts deliverability.
- General Best Practices: Poor email practices, like sending to unengaged recipients, affect deliverability more than simply linking to PDFs.
- Older Filters: Some older spam filters might flag PDFs.
Key considerations
- Content Review: Carefully review PDF content to avoid spam trigger words and misleading information.
- Domain Reputation: Ensure the PDF is hosted on a domain with a good reputation and warm up the domain correctly if new.
- PDF Optimization: Optimize PDFs for web viewing and proper formatting.
- Virus Scanning: Scan PDFs for viruses before uploading them to the web.
- Monitor Reputation: Actively monitor the reputation of the domain hosting the PDFs.
Marketer view
Email marketer from Reddit shares that linking to PDFs is generally safe, but the PDF's content should be carefully reviewed. Avoid using excessive images, spammy keywords, or misleading information, as this could trigger spam filters. Ensure the PDF is properly optimized for web viewing.
12 Jan 2025 - Reddit
Marketer view
Email marketer from Sendinblue explains that linking to PDFs is not inherently harmful to deliverability. Deliverability issues are more likely caused by poor email practices, such as using spam trigger words, sending to unengaged recipients, or having poor authentication records.
31 Aug 2024 - Sendinblue
What the experts say
4 expert opinions
Experts generally agree that linking to PDFs in emails isn't inherently detrimental to deliverability. Email filtering companies typically scan links, and the primary concern revolves around the reputation of the domain hosting the PDF. Maintaining a reputable domain is crucial, and using links to reputable external websites can improve trust. However, broken links can negatively impact deliverability.
Key opinions
- PDF Links Generally OK: Linking to PDFs in emails usually doesn't directly cause deliverability problems.
- Domain Reputation is Key: The reputation of the domain hosting the PDF is a primary factor in deliverability.
- External Links Can Help: Linking to reputable external websites can enhance trust and improve deliverability.
- Filters Scan Links: Email filtering companies scan links in emails, including those to PDFs.
- Broken Links Hurt: Broken links in emails can negatively impact deliverability.
Key considerations
- Maintain Domain Reputation: Ensure the domain hosting PDFs has a positive reputation.
- Use Reputable Links: Link to well-known and trusted external websites when appropriate.
- Check for Broken Links: Regularly check for and fix any broken links in your emails.
- Data Gathering: Gather sufficient data before attributing deliverability issues solely to PDF links.
Expert view
Expert from Spam Resource explains that using links to support your content is okay, as long as they're used appropriately. Links to well-known, reputable external websites actually assist in improving trust as it shows that you're not afraid to reference external content and are happy to provide users with a wider range of information. But if these are broken links then deliverability can be impacted.
6 Jan 2023 - Spam Resource
Expert view
Expert from Email Geeks responds that linking to PDFs doesn't seem like it'd be a problem from a deliverability perspective, although it's always a possibility because there are people in control of filters everywhere with strange and peculiar opinions. It wouldn't be the first thing he'd reach for without a bit more data gathering.
14 Aug 2022 - Email Geeks
What the documentation says
3 technical articles
Email providers like Google and Microsoft scan links in emails, including those to PDFs, for malicious content or phishing attempts. A negative domain or IP reputation, as tracked by services like Spamhaus, can cause emails with PDF links to be flagged as spam or blocked. While a direct impact on deliverability isn't always guaranteed, user trust and interaction can be affected by warnings about unsafe links. Therefore, ensuring PDF links are safe and hosted on reputable domains is crucial.
Key findings
- Link Scanning: Google and Microsoft actively scan links, including PDF links, for malicious content.
- Reputation Tracking: Spamhaus tracks the reputation of domains and IPs used in email campaigns.
- Impact on Trust: Unsafe PDF links can trigger warnings, negatively affecting user trust and interaction.
- Potential Blocking: Suspicious PDF links can cause emails to be flagged as spam or blocked by anti-phishing policies.
Key considerations
- Safe Content: Ensure PDF content is free from malicious material and phishing attempts.
- Reputable Hosting: Host PDFs on domains with a positive reputation, avoiding blacklisted domains.
- Monitor Reputation: Monitor the reputation of your domain and IP address to identify and address any issues.
- User Experience: Consider the user experience when linking to PDFs, ensuring they are easily accessible and provide value.
Technical article
Documentation from Microsoft highlights that anti-phishing policies in Exchange Online Protection can scan links in emails, including those pointing to PDFs. If the link is deemed suspicious, the email may be flagged as spam or blocked. Therefore, it's important to ensure that linked PDFs are hosted on reputable domains and have safe content.
10 Aug 2024 - Microsoft Learn
Technical article
Documentation from Google explains that Google's Safe Browsing technology scans links in emails, including links to PDFs, for malicious content. If a PDF link is found to be unsafe, users may see a warning message before accessing the file. While this doesn't directly impact deliverability, it can affect the recipient's trust and interaction with the email.
2 Nov 2021 - Google Workspace Admin Help
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