Summary
The consensus is that while some MUAs might make plain text URLs clickable, relying on this behavior can negatively impact email deliverability, especially within quoted-printable MIME parts. Improper URL formatting without <a href> tags increases the risk of triggering spam filters, leading to higher spam scores and reduced deliverability. This is partly due to similarities with spammer tactics, such as URL obfuscation. Furthermore, it results in inconsistent rendering across email clients and could expose potential attack vectors. Ensuring correct encoding of URLs, particularly with special characters in quoted-printable content, and adherence to HTML standards are crucial to maintain deliverability. Avoid URL shorteners, use real URLs within <a href> tags, and always test your emails to ensure consistent rendering and user experience.
Key findings
- Spam Filter Trigger: Improperly formatted URLs (without <a href> tags) can trigger spam filters due to obfuscation and spammer association.
- Rendering Inconsistencies: Email clients may not consistently render plain text URLs as clickable, leading to a fragmented user experience.
- Encoding Issues: Incorrect URL encoding, especially in quoted-printable MIME parts, can lead to misinterpretation by email clients and spam filters.
- Design Guideline Violation: Failing to use proper HTML URL formatting violates email design guidelines and can negatively impact deliverability.
- Potential Attack Vector: URLs without proper HTML tags could be exploited for URL security proxying attacks.
- URL Shorteners Bad: Using URL shorteners and redirects often mark emails as spam
- Avoid using Anchor Text: Email providers may penalize you for using anchor text
Key considerations
- Use <a href> Tags: Always enclose URLs within <a href> tags to ensure proper rendering, navigation, and avoid spam filters.
- Ensure Correct Encoding: Pay close attention to URL encoding, especially when using quoted-printable or special characters.
- Follow Email Design Best Practices: Adhere to established email design guidelines to maintain good deliverability and avoid triggering spam filters.
- Avoid URL Shorteners: Refrain from using URL shorteners and redirects in your emails.
- Test Email Rendering: Test your emails across different email clients to ensure consistent URL rendering and user experience.
- Do not include Anchor text: When using URLs include HTML formatting, do not use Anchor Text. Instead, use the full URL
What email marketers say
12 marketer opinions
The deliverability of emails containing URLs without proper HTML tags, particularly within quoted-printable MIME parts, is a complex issue with varying perspectives. Some argue that modern Mail User Agents (MUAs) automatically recognize and render plain text URLs as clickable, mitigating the immediate impact. However, the consensus leans towards potential negative consequences. Improperly formatted URLs can trigger spam filters due to obfuscation concerns and increased spam scores. Email clients may not consistently render plain text URLs, leading to a poor user experience. Furthermore, the lack of proper HTML tags can be seen as unprofessional and could be exploited as an attack vector. Best practices emphasize using <a href> tags for URLs, ensuring correct encoding, and adhering to email design guidelines to maintain good deliverability.
Key opinions
- Spam Filter Trigger: Improper URL formatting, especially without <a href> tags, can trigger spam filters and increase spam scores due to similarities with obfuscation techniques used by spammers.
- Rendering Inconsistencies: Email clients may not consistently render plain text URLs as clickable links, leading to inconsistent user experiences.
- Attack Vector: URLs without proper HTML tags could potentially be exploited as an attack vector for URL security proxying.
- Encoding Matters: Especially within quoted-printable MIME parts, ensuring correct URL encoding is critical to avoid misinterpretation by email clients and spam filters.
- Professionalism: Using proper HTML formatting, including <a href> tags, is seen as a more professional approach and increases trust with recipients.
- Anchor Text is Recommended: Wrapping URLs in anchor text is a poor practice that can negatively impact deliverability.
Key considerations
- Use <a href> Tags: Always enclose URLs within <a href> tags in your HTML emails to ensure proper rendering and reduce the likelihood of being flagged as spam.
- Encode URLs Properly: Ensure that URLs are correctly encoded, particularly if you are using quoted-printable MIME parts or including special characters.
- Follow Email Design Best Practices: Adhere to email design best practices to maintain good deliverability and avoid triggering spam filters.
- Test Across Email Clients: Test your emails across different email clients to ensure that URLs are rendered correctly and the user experience is consistent.
- Monitor Spam Scores: Regularly monitor your spam scores and deliverability metrics to identify and address potential issues related to URL formatting.
- Use Anchor Text: Wrap URLs with anchor text and only include the anchor text to avoid deliverability concerns.
Marketer view
Email marketer from Email Marketing Forum explains that using plain text URLs without <a href> tags can increase spam scores. Spam filters analyze email content for various factors, and improperly formatted URLs can contribute to a higher spam score, reducing deliverability. Use proper HTML tags to present URLs correctly and avoid spam filters.
3 Sep 2021 - Email Marketing Forum
Marketer view
Email marketer from Constant Contact shares that ensuring all urls are properly formatted with HTML is crucial to email deliverability. If the URLs are not formatted correctly, the content may not render as intended or may be flagged as suspicious.
24 Apr 2022 - Constant Contact
What the experts say
3 expert opinions
Experts emphasize that emails lacking proper HTML <a href> tags around URLs, particularly when using quoted-printable encoding, are more likely to be flagged as spam. Spam filters often view such emails as suspicious due to the potential for URL obfuscation and misinterpretation. Using real URLs within HTML tags, rather than URL shorteners or redirects, is crucial to avoid appearing like a spammer and maintain good deliverability.
Key opinions
- Spam Filter Suspicion: URLs without <a href> tags raise suspicion with spam filters, as spammers often use similar techniques.
- Quoted-Printable Issues: Improperly formatted URLs within quoted-printable encoding can be misinterpreted or flagged as spam.
- URL Shorteners Harm Deliverability: Using URL shorteners and redirects may cause emails to be marked as spam.
Key considerations
- Use Proper HTML Tags: Enclose URLs in <a href> tags for better deliverability.
- Avoid URL Shorteners: Refrain from using URL shorteners and redirects.
- Ensure Correct Encoding: Pay close attention to URL encoding when using quoted-printable encoding to prevent misinterpretation.
Expert view
Expert from Spam Resource explains that the use of quoted-printable encoding without proper URL formatting can lead to deliverability issues. When URLs within quoted-printable sections are not correctly formatted (e.g., missing <a href> tags or encoding errors), they may be misinterpreted or flagged as suspicious by email clients and spam filters.
20 Mar 2024 - Spam Resource
Expert view
Expert from Word to the Wise, Laura Atkins, explains that one of the ways to get your mail delivered is to not act like a spammer. Spammers often use URL shorteners or link redirects. You should use real URLs that include HTML tags, not link redirects, for better deliverability.
22 Jun 2023 - Word to the Wise
What the documentation says
4 technical articles
Technical documentation highlights that the absence of proper HTML <a href> tags around URLs, particularly within quoted-printable encoded content, creates multiple deliverability concerns. Incorrect encoding of URLs, especially with special characters, can lead to misinterpretation by email clients and spam filters. Rendering inconsistencies across different email clients can further worsen the issue, with some clients not automatically converting plain text URLs into clickable links. Adhering to email design guidelines and utilizing the <a> element ensures consistent rendering, proper navigation, improved user engagement, and reduced risk of being flagged as spam.
Key findings
- Encoding Problems: Improper encoding of URLs in quoted-printable sections results in misinterpretation by email clients and spam filters.
- Rendering Issues: Lack of <a href> tags leads to inconsistent URL rendering across different email clients.
- Reduced Functionality: Without <a href> tags, the functionality of the URL is reduced, impacting user engagement.
- Design Guideline Violation: Not using proper HTML URL formatting violates email design guidelines and can negatively impact deliverability.
Key considerations
- Proper URL Encoding: Ensure URLs within quoted-printable sections are correctly encoded to avoid misinterpretation.
- Use <a href> Tags: Always use HTML <a href> tags to ensure consistent URL rendering and proper navigation.
- Follow Design Guidelines: Adhere to email design guidelines to maintain good deliverability and avoid triggering spam filters.
Technical article
Documentation from Litmus explains that email rendering inconsistencies across different email clients can exacerbate issues related to URLs without proper HTML tags. Some clients may automatically convert plain text URLs into clickable links, while others may not, leading to a fragmented user experience. It is important to use proper HTML tags to ensure consistent rendering and avoid deliverability concerns.
4 Jul 2021 - Litmus
Technical article
Documentation from RFC Editor explains that quoted-printable encoding is used to represent data that mainly consists of printable ASCII characters but also includes non-ASCII characters or control characters. If URLs are not properly encoded within quoted-printable sections, especially if they contain special characters or non-ASCII characters, it can lead to misinterpretation by email clients and spam filters, affecting deliverability.
7 Oct 2021 - RFC Editor
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