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How to Fix CSS Flexbox Collapse in Outlook 2016
for Salesforce Marketing Cloud (SFMC) Campaigns

A programmatic integration guide for resolving email rendering crashes inside Outlook 2016 using Salesforce Marketing Cloud (SFMC)'s layout editor environment.

Root Bug Analysis

Outlook 2016 uses the Microsoft Word (MSO) which lacks support for standard rendering rules. This causes CSS Flexbox Collapse elements to break or collapse when rendering templates.

Active rendering engine: Microsoft Word (MSO)

Salesforce Marketing Cloud (SFMC) Specific Guide

Salesforce Marketing Cloud (SFMC)'s delivery wrapper can clean and restructure elements during import, creating dynamic spacing differences inside Outlook 2016.

Integration Step:

Create an 'HTML content' layout block in Content Builder. Paste the table structure. Enclose any custom merge tags inside standard AMPscript wrapper lines.

ESP Unsubscribe Alignment

When compiling custom HTML templates for Salesforce Marketing Cloud (SFMC), you must ensure your layout retains deliverability compliance loops. Salesforce Marketing Cloud (SFMC) requires you to insert their specific unsubscribe merge tag, otherwise your campaign delivery will be flagged by automated spam audits.

Salesforce Marketing Cloud (SFMC) Unsubscribe Tag:%%unsubscribe_url%%

Documented Client Behavior

Expected layout behavior based on target rendering engine specifications:

Documented behavior: CSS Flexbox Collapse causes elements to stack vertically or clip in Outlook 2016 when templates are sent from Salesforce Marketing Cloud (SFMC).

Interactive Salesforce Marketing Cloud (SFMC) Custom Sandbox

Target Environment: Outlook 2016

Auto-compile fixes inside RenderOps Workspace

Load layout code directly into our Retrofit Compiler to compile responsive table frameworks that display cleanly in Outlook 2016.

Launch Retrofit Compiler

Fix CSS Flexbox Collapse on Other clients for Salesforce Marketing Cloud (SFMC)