Outlook Email Broken Layout Fix: Resolve Outlook Button Border Collapsing for Deliverability & Spam Audits
Spam filters analyze email HTML code quality alongside body copy. Unclosed tags, excessive styling block nesting, and broken link parameters are flagged as spam risks. Below is the targeted integration guide to fix Outlook Button Border Collapsing inside Outlook 2019 templates when using Brevo (Sendinblue).
Technical Breakdown
Outlook 2019 uses the Microsoft Word (MSO) which lacks support for standard rendering rules. This causes Outlook Button Border Collapsing elements to break or collapse when rendering templates.
Brevo (Sendinblue) Behaviors
Brevo's rendering system injects inline spacing helpers to support their responsive editor, which can cause column overlaps in Outlook. Using explicit table alignments is required. Run your finished layouts through the Spam Word Auditor to catch trigger phrases and verify structural delivery alignments before launching.
Remediation Code Block
To guarantee perfectly rounded buttons inside Outlook, we must generate a hybrid VML (Vector Markup Language) roundrect structure overlaid with normal HTML tables. VML is read only by Outlook, while WebKit clients read the HTML layout. In your Brevo (Sendinblue) campaign manager, make sure you configure your links to run via {{ unsubscribe }}.
<!--[if mso]>
<v:roundrect xmlns:v="urn:schemas-microsoft-com:vml" xmlns:w="urn:schemas-microsoft-com:office:word" href="{{ unsubscribe }}" style="height:44px;v-text-anchor:middle;width:200px;" arcsize="15%" stroke="f" fillcolor="#720e9e">
<w:anchorlock/>
<center style="color:#ffffff;font-family:sans-serif;font-size:13px;font-weight:bold;">Click Here</center>
</v:roundrect>
<![endif]-->
<!--[if !mso]><!-->
<table role="presentation" border="0" cellpadding="0" cellspacing="0" style="border-collapse:collapse;">
<tr><td align="center" bgcolor="#720e9e" style="border-radius:6px;"><a href="{{ unsubscribe }}" style="padding:12px 24px;color:#ffffff;display:inline-block;text-decoration:none;font-weight:bold;">Click Here</a></td></tr>
</table>
<!--<![endif]-->Live Code Sandbox Test
How to Deploy inside Brevo (Sendinblue)
Copy the fixed VML or table wrapper code block from the remediation box above.
Open Brevo's template canvas, select the element you wish to configure, click 'Edit HTML' or insert a standalone 'HTML' content block, and paste the code.