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

Last Updated: January 26, 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 or PowerPoint.

If you directly try to format your signature table in OneNote you may have issues with formatting, fonts, and style. If this is a concern, create the table in OneNote, copy the table to Outlook, and then fill in the table cells. Below are the steps.

Fix your signature using OneNote to create the table layout:

In OneNote, Add Page to a section and select to add text.
From the Insert Ribbon, select table and select the desired size. Example, 2×3.
After the table is added, merge any cells if needed.
Select this table and copy and paste it into a new Outlook message that has your signature in it.
If the borders are not showing on your signature (maybe because they are white), turn them back on.
Now size the width of the table cells to match your signature.
Copy and paste the contents of each cell from the signature into the new table.
Fine tune any formatting.
Turn the border off for the new table.
Select the fixed signature and use Ctrl-C to copy to the clipboard.
From the Message Ribbon, select Include > Signature > Signatures …
Replace and Save the signatures with this new “fixed” one.
You can delete the OneNote page used to temporarily create the table layout.