Use Litmus in the Legacy Email Composer to preview how your message renders across many email clients and devices. This helps you confirm your layout, images, and formatting look correct before sending.
Quick Reference (Advanced Users) – Click to Expand
- Open your message in the Legacy Email Composer.
- Select the Review tab.
- Click the Litmus icon to run a preview.
- Scroll through client previews on the right and select one to review.
- Use Customize Clients to manage which Litmus clients appear in Act-On.
- Make content changes in Design, then re-run Litmus.
Try it like this: Open the Review tab, run a Litmus preview, check how your columns behave in Outlook and Gmail, adjust your table spacing in the Design tab, then generate a new Litmus preview to verify improvements.
Requirements
To use Litmus testing inside Act-On, you need:
- An active Litmus Core or Enterprise account.
- Your Litmus credentials connected in Act-On: Settings → Connectors → Other → Litmus.
Open Litmus in the Legacy Email Composer
To access Litmus previews for a legacy message:
- Open your email in the Legacy Email Composer.
- Click the Review tab.
- Click the Litmus icon.
Act-On sends the message to Litmus and returns a set of previews.
Review your Litmus previews
Select any client listed on the right side of the screen to view how your email renders in that inbox.
Use these previews to check for:
- Table layout issues (common in Outlook)
- Spacing or padding changes between clients
- Font substitutions
- Image scaling problems on mobile
- Stacking behaviour for multi-column layouts
Tip: Legacy emails rely heavily on table-based HTML. Small adjustments to cell padding, image width, or nested tables often fix rendering issues highlighted by Litmus.
Customize which Litmus clients appear
You can choose which email clients Act-On displays during Litmus testing.
- In the Litmus preview panel, click Customize Clients.
- This opens your Litmus account where you can select or deselect clients and devices.
Act-On will only show the clients you select in Litmus.
Make edits and re-test
If you see issues in your previews:
- Return to the Design tab in the Legacy Composer.
- Adjust spacing, table structure, image sizes, or fonts.
- Return to Review and run Litmus again.
About Litmus usage
- Your Litmus subscription determines how many previews you can run per month.
- Each preview run in Act-On consumes Litmus credits.
- Re-running previews for the same message uses additional credits.