Email Signature has just added borders to a table that did not have them as recently as 23/12/2025

MP007 115

I have a table in my email signature that has no borders showing. This ha been the case for over 1 year and last email set on 23/12/2025 was still borderless in the signature. Today there are borders and I cannot see how to remove other than manually in the email every time. There appear to be no settings that have caused this and nothing has changed from the user / client perspective as far as I can tell.

David Musgrave MVP 165 Reputation points MVP

2025-12-30T00:56:05.61+00:00

I have this problem too.

They are NOT the dotted Gridlines as Harold mentioned. They are actual lines, so every email I send, I have to select the table in the signature and manually turn the border off.

If you look at the signatures in the Outlook Signature and Stationery window, after the last Microsoft 365 update, the signatures now have visible borders when before they did not. The editor does not have the ability to turn the borders off. If I copy and paste a signature with the borders off into the window, the borders become visible again.

So, it is impossible to fix the signature. It is no longer possible to have a signature with a table without borders.

This is a very annoying bug introduced in the latest Microsoft 365 update. Sadly, I can no longer roll back the update because I tried a repair, which uninstalled and re-installed everything and prevents a rollback of just one update.

See details and workaround solutions in my blog

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/

David Musgrave
Microsoft MVP
MP007 115 Reputation points

2025-12-30T10:02:07.53+00:00

Hi David - you are correct, they are not dotted lines and there appears to be that when adding a table into a signature, regardless of borders being visible or not when adding to the signature, they are visible when using the signature and I cannot establish an easy solution other than editing the signature on every email!!
Jon Bentley 0 Reputation points

2025-12-30T14:12:32.63+00:00

I, too, have been unable to remove the lines from the table. It seems to show up only on replies/forwards and not the original e-mail.
Jeremy Henry-Tan 5 Reputation points

2025-12-30T18:01:49.8433333+00:00

I also have this issue, and like MP007, my last email sent on 12/23 did not have a signature with a table outline/border enabled. This must have been due to a recent change.
Wouter Buijze 0 Reputation points

2026-01-04T12:34:02.82+00:00

Also have this problem. Its very annyoning
Craig W 0 Reputation points

2026-01-05T02:30:38.9733333+00:00

I have the same issue - emails in the last few days now render a border, despite there not being one when I open the signature.htm file in AppData directly.
Arjan Teunissen 10 Reputation points

2026-01-05T13:31:22.5166667+00:00

I am experiencing the same issue on computers with MS 365 MSO Version 2512 Build 16.0.19530.20038. This issue is not present on previous Versions 2511.
Jason 10 Reputation points

2026-01-06T05:33:43.03+00:00

Agree - very annoying. The only workaround I found that seems to work is to go to your original file in Word, set your borders to 0.5pt & colour them white, then copy & paste into your email signature. That way they'll disappear on a white background.
Jennifer Dyer 0 Reputation points

2026-01-12T15:32:32.37+00:00

Thank you Jason - it's not a solution, but at least it's a functional work around for now.
Brendan Radich 0 Reputation points

2026-01-14T21:02:59.2633333+00:00

I gave up on waiting for a solution to this. Microsoft Support did provide a template for HTML table formatting following Outlook best practices (attached).

I fed that sample to Claude 4.5 Opus, gave it a sample of our current signature, and ended up creating a custom SharePoint app. Now, we have a Signature Generator app on our intranet that pulls in MS Graph data from AD to auto-fill the users details, give them opportunity to change it, and then copy & paste into Outlook.

This issue sucked, but I think we ultimately landed on a better signature solution because of it.

MS Support Signature Sample.txt
G 5 Reputation points

2026-02-18T17:55:15.8533333+00:00

I also have this issue!
David Musgrave MVP 165 Reputation points MVP

2026-02-18T23:18:04.5633333+00:00

Hi G. This issue is fixed in the latest office updates and there are a number of good workarounds in my article:

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/

David
G 5 Reputation points

2026-02-19T16:32:40.54+00:00

I updated Outlook and still have the issue.
Gabe Bratton 776 Reputation points Microsoft Employee Moderator

2026-02-19T17:30:06.7466667+00:00

G, what is the Outlook SKU e.g. M365 subscription, Office 2024, etc.?

What is the version and build (click File, Office Account, under About Outlook)?
As far as I know the issue is fixed everywhere but I can test and double check if I know what Outlook SKU and build you are running.
G 5 Reputation points

2026-02-19T18:39:05.54+00:00

@Gabe Bratton It is the Microsoft 365 subscription. Version 16.106.1 (26021521)
Gabe Bratton 776 Reputation points Microsoft Employee Moderator

2026-02-19T19:13:17.75+00:00

G, based on the build you are running that appears to be Outlook for Mac, https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac. I found a Mac Outlook bug logged for signature spacing not being correct, but there is no ETA yet. To help give the bug priority please submit an In App ticket from Mac Outlook describing the issue, https://support.microsoft.com/en-us/office/contact-support-within-outlook-for-mac-d0410177-8e65-4487-93f7-206a3a3d71a8. If I get any updates about when the issue will get fixed, I will share back.

16 answers

David Musgrave MVP 165 Reputation points MVP

2026-02-04T03:37:10.54+00:00

As at 04-Feb-2026: The Microsoft 365 (Office) update, Outlook Version 2601 (Build 19628.20166 Click-to-Run) does finally fix the issue.

Article has been updated:

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/
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JamesYoung-5174 5 Reputation points

2026-01-22T18:43:33.42+00:00

Another call out if the MsoTableGrid fix doesn't work, use a text editor to open the HTM file (C:\users*yourusername*\appdata\roaming\microsoft\signatures) and change the "borders" entries from "solid" to "none". Worked for multiple users where the other fixes did not.
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David Musgrave MVP 165 Reputation points MVP

2026-01-22T18:46:41.6633333+00:00

Once the class=MsoTableGrid has been changed to class=MsoNormalTable, if you edit the borders in Outlook (in a message) you can set them to none and that is honored. I will update my article with your feedback, so it can be handled without the extra formatting after editing the HTML file. I found that the following find and replace

mso-border-alt:solid to mso-border-alt:none

was more important than

border:solid to border:none

Also, a simple find and replace might miss a table cell if the command is split over two lines.

JamesYoung-5174 5 Reputation points

2026-01-22T18:58:01.61+00:00

Awesome! Thank you for adding that. Really appreciate your article!

David Musgrave MVP 165 Reputation points MVP

2026-01-22T19:38:10.15+00:00

@James Young The article is updated and you have been credited. 😊 https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/
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David Musgrave MVP 165 Reputation points MVP

2026-01-21T15:38:15.4933333+00:00

Hi everyone

Thanks to input from Gabe Bratton (Microsoft Support) and some research and testing of my own, we now have 2 solutions that work in all situations (including Dark Mode, thanks Brian G).

Both of the solutions actually achieve the same result of changing the internal table type used in the HTML fiel from "class=MsoTableGrid" to "class=MsoNormalTable".

I have updated Workaround 4 (editing the HTML file directly) and added Workaround 5 (using OneNote to create the table layout) in my article.

Both of these methods work, but if you are happy to edit the HTML file (Workaround 4), you will find that less work overall.

I am reposting the article link here so you don't have to go find it elsewhere in this thread.

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/

Microsoft are aware of the issue and hopefully it will be fixed soon, regardless of internal table type.

Thank you to everyone who provided ideas for solutions.

Kind regards

David
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MG 0 Reputation points

2026-01-07T02:56:45.08+00:00

A temporary workaround.

When you start an new email, click the signature table in your email with the borders showing, click Table Design, Borders, No borders. This will turn them off for that email only. I tried copying the corrected table out of the email and into the signature and saving it but it did not work. We have a new unwanted feature it would appear. Painfull but it is a work around for now.
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David Musgrave MVP 165 Reputation points MVP

2026-01-14T02:52:12.2466667+00:00

See details and workaround solutions in my blog

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/
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Harold Milan 17,495 Reputation points Independent Advisor

2025-12-29T14:14:21.67+00:00

Hi,

Those dotted lines aren’t real borders they’re gridlines that Outlook shows to help you see the table layout. They don’t print or appear in sent emails, but they can look annoying while editing.

I suggest is:

Open Outlook and go to the email where you see the dotted lines.

Click inside the signature table.

Go to Table Tools → Layout on the ribbon.

Look for View Gridlines and click it to turn it off.

I hope this helps!
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David Musgrave MVP 165 Reputation points MVP

2025-12-30T00:58:09.72+00:00

These are visible borders, not gridlines. They have been turned on in the master signatures and cannot be removed in the Signatures and Stationery window and copying and pasting into the window just turns the borders back on. This is a bug introduced in the latest Microsoft 365 update. See details and workaround solutions in my blog

https://winthropdc.wordpress.com/2026/01/08/msoffice-hiding-signature-table-borders-in-microsoft-outlook/

Marx Seegers 0 Reputation points

2026-01-06T11:24:25.2266667+00:00

Hi, will there be an update regarding this topic? Gridlines are automatically added and cannot be removed in the signature editor. I have the problem with replying to emails, not new emails. Seems like a software bug.

Andy small 0 Reputation points

2026-01-06T12:04:40.6833333+00:00

Exactly the same issue here on both new e-mails and when replying. Definitely table borders. Tried creating a new signature where there are no visible borders on the table and it still magically creates them for me. Very frustrating having to adjust every e-mail I send!! hope this bug is fixed quickly

MG 0 Reputation points

2026-01-07T02:55:38.46+00:00

You shouldn't comment if you don't know what you're talking about. They are solid borders, not dotted grid lines, that weren't there late last year 2025.

When you start an new email, click the signature table in your email with the borders showing, click Table Design, Borders, No borders. This will turn them off for that email only. I tried copying the corrected table out of the email and into the signature but it did not work. We have a new unwanted feature it would appear. Painfull but it is a work around for now.
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Email Signature has just added borders to a table that did not have them as recently as 23/12/2025

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