Why is HTML Sanitizing Important?

When it comes to email delivery, HTML sanitizing can be extremely helpful in avoiding the spam box.

Many email clients and spam filters have strict guidelines regarding what types of HTML code are allowed in emails, and any suspicious code can cause the email to be flagged as spam or blocked entirely. By using an HTML sanitizer to remove any code that could be seen as suspicious or malicious, email senders can greatly increase the chances of their emails making it to the recipient’s inbox.

In addition to protecting against spam filters, HTML sanitizing can also improve the overall user experience by ensuring that emails are displayed correctly across all email clients and devices. This can help to build trust with recipients and improve engagement rates, leading to more successful email marketing campaigns.

Examples of HTML Sanitizing

Before sanitizing


After sanitizing


In this example, the meta tag was removed because it’s not necessary for email rendering, and the script tag was removed because it’s potentially harmful and may trigger spam filters in some email clients. The other differences you see was that the <h1> tag was converted to a <p> tag, because the H to P Tag Conversion option was turned on in this example as well.

Video Overview of HTML Sanitization

HTML Sanaitizing Use Case

ABC Corporation is a large multinational corporation that relies heavily on email marketing to reach its customer base. They have noticed that their email deliverability rates have been steadily declining, and they suspect that their HTML code might be to blame.

To address this issue, they decide to use Campaign Cleaner’s HTML sanitizing feature. This feature analyzes their HTML code and removes any potentially harmful elements or attributes, such as scripts or iframes, that could trigger spam filters or cause rendering issues in some email clients.

After using Campaign Cleaner to sanitize their email templates, ABC Corporation sees a noticeable improvement in their email deliverability rates. Their emails are no longer being flagged as spam, and they are seeing higher open and click-through rates. They continue to use Campaign Cleaner regularly to ensure that their HTML code is always clean and optimized for maximum deliverability and engagement.