Classic Outlook adds table borders to signatures after updating to Version 2512

Last Updated: January 20, 2026

ISSUE

After classic Outlook updates to Version 2512, existing email signatures add table borders. This issue happens because Word is setting the border to a non-zero border set. You can confirm this by using Word to create a table and set it to no border and then paste into OneNote or PowerPoint. Outlook uses Word as its rendering engine, so the same issue will occur when creating the table in an email in Outlook.

STATUS: INVESTIGATING

This issue has been escalated to the Word Team for investigation. We will update this topic as soon as we have any updates to share.

WORKAROUND

To work around the issue, create your signature table in OneNote and then paste it into the signature box in Outlook.

Additional Resources

Create and add an email signature in Outlook