Problems with email signatures in Office 365

In Office 365, there are some situations in which your email signatures stop working. Here is a quick access list of the most frequent email signature management problems, with solutions:

Office 365 signatures cannot be edited

Sometimes, when using your Office 365 Outlook on the web (OWA), you might experience a problem when trying to set an email signature for your account. When going through email settings, under Layout menu, the Signature button might be missing. This makes it impossible for users to make any changes to their Office 365 email signatures. The most probable cause is OWA policy blocking this feature. Here is how to fix it:

  1. Access your Exchange admin center and go to the permissions section.

office 365 email signatures not working cannot be edited 1

  1. Then, select the Outlook Web App policies tab in the top menu. Choose the policy which is in action (OwaMailboxPolicy in this example) and edit it.
  2. In the features tab, click More options at the bottom of the window.

office 365 email signatures not working cannot be edited 2

  1. Under the User experience section, select the Email signature checkbox.

office 365 email signatures not working cannot be edited 3


  • This feature can be used the other way round in case there is an email signature/disclaimer added through mail flow rules or a third-party tool, and you want to block user-made signatures.
  • If an email signature is added prior to blocking this feature, users will still be able to use it. It can be even added automatically if such an option has been chosen.
  • OWA policies, as expected, are not applied to users who access their mailboxes in Outlook.

If you are not sure how to set an Office 365 email signature, this article may come in handy.

Back to the list of problems

No images in Office 365 email signatures

office 365 email signatures not working no image

Have you added an image to your email signature, but it is not displayed? Have you struggled with the dreaded red x showing instead of your marketing banners or social media icons? This might have happened because you have used a linked image (aka hosted image). Linked images are blocked automatically by most email clients. What is more, if a web location where the image is stored becomes temporarily or permanently unavailable, the image will not be displayed. Neither will it display while browsing emails in offline mode. You can fix this issue by using embedded graphics instead:

  1. Click the picture icon in the signature editor window and choose a picture from your local drive.

office 365 email signatures not working no image 2


  • Images in this option are sent as hidden attachments, increasing the email size.
  • On rare occasions, such images can be deleted by the recipient’s anti-virus software.
  • If you want to ensure your embedded images look correctly on the recipient’s side, you have to use a third-party solution like CodeTwo Signatures for Office 365.

You can read more on the differences between linked and embedded (inline) pictures in this blog post.

Back to the list of problems

Double spacing in email signature block

While editing an HTML email signature in OWA or Outlook, it is quite common that your template does not display the way you designed it. The most frequent problem is double line spacing:

office 365 email signatures not working formatting problem double line spacing

Although there are quite a few ways to solve the problem, there is one which tends to work for every formatting-related problem, including the issue with double spacing:

  1. Start from creating your email signature block in a word processor or email signature generator;
  2. Copy and paste the email signature you have created into the signature editor;
  3. Make final adjustments, if necessary.

The double-spacing problem could also be solved by using Shift + Enter key combination, instead of starting a new paragraph by simply pressing Enter. However, sometimes it might cause the signature to appear as just one line of text. The solution above guarantees that the problem is solved. Apart from that, it gives you more editing options than the built-in OWA or Outlook email signature editor.

Back to the list of problems

Office 365 email signature grayed out

This issue might occur if you access your Office 365 email account in Outlook. If you cannot change or add a new email signature, this is most likely caused by a certain value entered into Registry. It has nothing to do with Office 365 Administration, it is entirely dependent on Microsoft Window’s functionalities. In order to repair the issue, follow those simple steps:


  • Playing with the Registry might prove to be a bad idea if you haven’t done it before. Be sure to always create a registry backup before you start working on it. This can be done by clicking File > Export… and choosing a target location for your backup.
  • Additionally, there can be value NewSignature and Reply_Signature with value type REG_SZ and value data set to name of the signature which is to be added automatically. Those Registry entries should also block changing signatures.
  1. On your keyboard, hold the Windows icon and press R.
  2. Type regedit and press Enter.

problems with email signatures in office 365 not working greyed out

  1. This will open the Registry editor. In the folder tree on the left, follow the path: HKEY_Current_User > Software > Microsoft > Office > X > Common > MailSettings
  2. If there is a value named DisableSignatures and is set to 1, modify it so that it is set to 0.

problems with office 365 email signatures not working greyed out

Back to the list of problems

Email signatures don’t show up directly under replies or forwards

A well-known issue often discussed among Exchange Online administrators is email signatures landing at the bottom of email conversations. Unfortunately, Exchange Online does not provide a way to overcome this problem natively. What is more, if you do not add an exception to your mail flow rule, you may experience your email signature being doubled.

Currently, the only way to automatically add email signatures directly under replies or forwards is to use a third-party solution. Your best bet would be trying out CodeTwo Email Signatures for Office 365.

Back to the list of problems

Office 365 email signatures are not displayed in Sent Items

Another issue that companies often face is that email signatures inserted on the server’s side are not visible in the sender’s Sent Items folder. This might cause problems if you have a disclaimer that should be attached to every sent email, but you are not able to verify it. Not including disclaimers in your emails may cause problems of legal nature.

There is a workaround – instead of appending disclaimers on the server level, you can create one email signature template and distribute it to all users. Then, just instruct them to insert the disclaimer in their email clients.

Unfortunately, although it solves one problem, it may generate a list of new ones. To name a few:

  • Employees may fail to implement the email signature or simply ignore the request to set it up.
  • In case users use more than just one email client, the signature may look differently across the company.
  • Every change to email signature would have to be implemented on all the machines every time it occurs.

In order to view Office 365 email signatures and disclaimers in the Sent Items folder, you will need to use CodeTwo Email Signatures for Office 365 – the first Office 365 signature manager on the market to offer such a feature.

These are the most frequent problems you might experience with email signatures in Office 365. If you experience any other issues, be sure to let us know about them in the comments. We will try to address those problems to the best of our abilities.

48 thoughts on “Problems with email signatures in Office 365

  1. Calvin

    I am running into an issue where I was able to load a picture of the company logo into the signature but the sizing is all wrong. I am unable to edit the size of the logo (without the usual drag corners to resize) and unable to delete it either. Has anyone else run into the same issue?

    1. Kamil Glaser

      It is a good practice to resize the logo you want to have in your email signatures using a graphics editor. This way, your logo will have the dimensions you require and the email size will be reduced. To delete a picture, you should highlight it the same way you would highlight a part of text, and then hit the delete key.

  2. lydia

    Im having an issue where I want to use a jpg image in my signature, and when I send a test email to myself, it looks great. However when anyone else gets my email, there are 2 duplicate logos included in my signature.

  3. Cara Maxwell

    When I reply to some email strings, there is one of my peers email addresses added to my signature. It reads Why is this happening?

    1. Kamil Glaser

      Hello Cara,
      Is the “mailto link” added to your email address? Can you see this link in your Sent Items folder? Some email clients (including Outlook) add mailto links to any email address automatically.

  4. Armand

    I am running into an issue where when I set a default account for one signature, it is changing it for all the others. I want to use a specific signature for each email account, but when I change one, it is changing all the other ones on the list.

  5. Wayne Hanks

    My issue is that when data is removed from an AD field ( for example, the mobile phone field, ) it does not refresh the auto signature, and still retains the original data.
    Is there any way of forcing the signature to recognise that there should not be a mobile phone in the field? I am just trying putting a number of spaces in the field to see if this works.

    1. Kamil Glaser

      The change in AD will not work on email signatures retrospectively. Do you experience the problem for the emails sent after the change in AD? Also, the only way to remove signaling phrases when an AD attribute is null is to use a third-party software, like CodeTwo Email Signatures for Office 365.

  6. Mar

    I did create my email signature in a word processor and yet it is still double spacing when I sent and reply to emails. Help!

    It shows up in the signature generator as not spaced, yet when it sends it….

  7. Jim M.

    Trying to delete an OWA email signature … can delete the text OK, but a couple of graphic lines cannot be removed by highlight/Delete, backspacing, etc.

    1. Kamil Glaser

      Hi Jim,
      To delete all email signature content, you can click inside the signature editor box, select everything using the ctrl+a key combination and press delete. Mind to save the changes.
      Keep in mind that even if you delete all content from your email signature, some invisible formatting tags might still remain. To get rid of them, you can, for example, paste a signature with the correct formatting from MS Word (or any other word processor).

  8. Paul B

    After upgrading to Office 365 using my hosted work Exchange account when anyone replies to an e-mail I send, our company logo from my signature gets added as an attachment. The logo is then removed from my original e-mail signature in the reply and has the red X box with “the linked imaged cannot be displayed”. My signature worked fine before upgrading to 365. I tried adding a hosted logo instead of an embedded one and am getting the same result. Any thoughts? Thanks in advance

  9. Jake

    When I put in the signature block on the online portal (, the signature displays fine and correctly. However, when i put the same signature into the signature editor into the outlook application itself, it doesn’t. What’s going on??

    1. Kamil Glaser

      Hi Jake,
      I’d like to help you, but I need more information. Could you specify what kind of issues you experience in Outlook? Also, how did you create the signature in the first place?

  10. Christie

    When replying or forwarding to an email…the body of the existing email thread starts on the same lines as my signature. How do I format this?

    1. Kamil Glaser

      Do you mean that the signature gets pushed to the bottom of the email thread? If that is the case, it is a very common problem with global email signatures applied via mail flow rules in Office 365 and on-premises Exchange Server. The only way to fix this problem is to use a third-party tool instead: CodeTwo Email Signatures for Office 365.

  11. Laurie

    When I add my signature to an email, the signature populates at the top of the email instead of at the bottom, like a true signature… any ideas?

    1. Kamil Glaser

      Is this a global Office 365 email signature, or just your personal email signature you add manually?
      If it is a global Office 365 email signature, go through the settings in Exchange Admin Center and make sure you append the signature, and not prepend it.
      If this is a personal email signature, make sure you add it when the cursor is at the bottom of the message, or highlight it and move it manually to the bottom.

  12. Cody Griffin

    My signature is normally purple and gray. However, sometimes when I forward a message, my signature is all black. What is causing this? It is not happening on every forward but only on some of them. Any advice?

    1. Kamil Glaser

      In most cases, such problems are caused by sending a message in plain-text format. For example, if you forward a plain-text message, both Outlook and OWA will automatically use the same format, removing all of your formatting (color, images and styles).

  13. KMH808

    I can’t get my email signature to actually look like what I put in the signature box. It has most of the info, but won’t show my logo and uses plain black text instead of what I’ve added to the box. Very frustrating and it’s driving me crazy because I can’t figure out how to fix it! Any suggestions? Thanks.

    1. Kamil Glaser

      Are you using Outlook on the Web? It sounds like you are trying to add a HTML email signature to a message which is in plain text format. Messages are converted to this format each time you forward or reply to a plain-text email. When you create an email, check if under the More options button there is an option to “Switch to HTML”. When using the desktop version of Outlook, you can change format under the Format text tab.

  14. Dan

    Having an issue adding photo & logo to email signature (web outlook) the picture icon in setup is blocked/unclickable.

    1. Kamil Glaser

      Hi Dan,
      Are you using “the new Outlook” experience, or the good old version of Outlook on the Web? Also, check if you can paste an image (without using the button). As a test, you can paste a complete signature from the free email signature generator and see if the images are added.

  15. Sarah

    On office 365 I will go in to edit my email signature and it saves to the format I want, but when I send an email it will start breaking up words in to different lines. For example:

    when I save it:
    name, title
    company, location

    when an email sends:
    first name
    last name, title
    company, part of location
    part of location

    I have copied and pasted the text I want from a google doc because I wanted more colour options. Not sure if that makes a difference.

    1. Kamil Glaser

      Hi Sarah,
      Copying email signatures from different sources can end up in such formatting disasters. That is because you copy the text and formatting information which can be interpreted differently for Google Docs and for Office 365 signatures. You can try using Microsoft Word instead, as it tends to work better with the Office 365 email signature editor. You can also use one of the templates from the free email signature generator to create an OWA-compatible signature design.

  16. Marlene Caryk

    5/23/2019 does it yet again! Very thoughtful site and a thought-provoking post. Thanks!

  17. Nathan

    Hi, Massive thanks for this article really appreciated. Hoping I haven’t missed this in previous responses.

    When I’m replying through 365 it doesn’t show the signature when I build the email reply, then the recipient receives 2 lots of signature at the bottom of my response.

    I’ve checked my signature and everything looks fine.

    How do I stop this from happening?

    1. Kamil Glaser

      Hi Nathan,
      When you create your email signature in Outlook on the Web, you can choose to either use the email signature automatically for new messages only, for replies and forwards, or for none (then you need to add it manually).
      The most important issue though, is that since your recipient receives multiple signatures at the bottom of the message, you most likely have server-side email signatures set up in your tenant. Native Office 365
      global email signatures work this way. The only way to fix it is to use an Office 365 email signature tool, add an exception to the mail flow rule responsible for adding the signatures or to delete the rule. Each of those options require your Office 365 admin’s intervention.

  18. du do

    hi, we are having an issue with user using owa outlook client, after some period of time, logo image in their signature gets replaced with an image containing text cid:image1.png@some random text.
    is this server side issue?

    1. Kamil Glaser

      It might be a server-side issue. Is the logo uploaded to an image hosting service? The direct URL to the image might have changed.

  19. Millie


    I am able to access and edit my signature with font, colour, sizing and image with no issue for my office 365 account on the outlook website, however, when using the outlook app the signature disappears. When I go to the signature option on the app, I can only add text with no formatting options (my company have a strict house style). When I add at least this in a basic format, it still does not actually appear. How do I get my original signature settings to stick to my whole account and not just when I access it via the website.


    1. Kamil Glaser

      Hi Millie,
      The signature settings are not synched accross different apps. What’s even worse, different apps and email clients have different formatting options which results in having, at the very best, multiple similar email signatures. The only foolproof way of unifying the design across different apps and devices is to use email signature management software – CodeTwo Email Signatures for Office 365.

  20. Russell

    I have created an email signature in HTML and replaced the code in the HTM file in the signatures folder. Inline styling is all in place, the problem seems to be that any other styles set (in the head) or below the first body tag appear to be stripped out. This seems to include classes being removed from elements as well.

    I’m guessing this has something to do with it being translated into an MS Word rendition of the original HTML.

    I would like to keep the CSS style sheet in place (even if it is of no use to Outlook), so that if the customer’s email client has better support, for say media queries, then they will get an enhanced and responsive version.

    Is this do-able?

  21. Eric

    Hi have disabled the email signature policy in the exchange center under OWA policies.
    But one of my users use the Outlook mobile app and there signature is still there.
    How can i get rid of this ?

    1. Kamil Glaser

      Hi Eric,
      Like mentioned in the article, disabling the option in the policy is not enough to delete the signature. The easiest way to get rid of the user-made signature is to use PowerShell and:
      Get-Mailbox {your user} -RecipientTypeDetails UserMailbox | Set-MailboxMessageConfiguration -SignatureHTML " " -AutoAddSignature:$false

  22. Anders

    I have a question regarding using tables in ones signature.
    In my line of work, I occasionally send out tables that my clients then have to fill out. I have made this table as a signature to speed up the process of sending them. Unfortunately, my clients change the table i.e. deleting lines as they please instead of leaving them empty which is incompatible with the further process.
    Therefore, is it possible to somehow lock the table in my signature, so it can’t be changed by the receiver?

    1. Anders

      In addition to last: As well as locking the table, is it possible to lock the tabs, so no rows or columns gets deleted while you can still write in the spaces. So it becomes a fixed form but the content can be changed?

      1. Kamil Glaser

        Hi Anders,
        As far as I know, there is no way to lock a table like you described. You can; however, create an online form and link to it from the signature. Most online form creating tools allow a high level of customization, so you should be able to modify your form however you like, not worrying about recipients deleting any fields.

  23. Erik Jensen


    I keep getting an old signature when I send e-mails, even though I have no signatures saved. When I send an e-mail without any visible signature, it still shows up in the receiving end. When I have created and saved a signature, my recipients still end up getting two signatures from me.

    So my question is how do I delete a signature that I cannot find anywhere, but the people I send e-mails to still get!

    1. Kamil Glaser

      Hi Erik,
      It is possible that your emails are stamped with an organization-wide email signature. If that’s the case, you probably shouldn’t use your own personal signature. Either way, it will be best to discuss this with your IT department.


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