How to Change Signature in Outlook: A Guide

To change your email signature in Outlook, open a new email or go to Settings, choose Signature, edit your text or layout, and set it as default for new messages and replies. On Windows or Mac desktop, access Signatures through File Options or Preferences, while Outlook Web and Mobile use the gear icon or profile settings to update across accounts.

This guide provides exact step-by-step navigation paths for every major version of Microsoft Outlook, including Classic Outlook for Windows, the New Outlook app, Outlook Web, Outlook for Mac, and mobile apps on iOS and Android. It also covers Microsoft Cloud Signatures roaming rules, HTML formatting guidelines, and troubleshooting procedures for common display bugs.

Comparing signature settings across Outlook versions

Microsoft handles email signatures differently depending on the application interface and account type you use. Below is a detailed breakdown of configuration locations, formatting capabilities, and syncing behavior for each platform.

Outlook Platform	Navigation Path	Cloud Syncing	Formatting Support	Multiple Signatures
Classic Outlook (Windows)	File > Options > Mail > Signatures	Yes (Microsoft 365 accounts)	Full HTML, CSS, & Inline Images	Yes
New Outlook (Windows)	Settings Gear > Accounts > Signatures	Yes (Native Cloud Signatures)	Standard HTML & Images	Yes
Outlook Web (OWA)	Settings Gear > Mail > Compose and reply	Yes (Server Source)	Standard HTML & Images	Yes
Outlook for Mac	Outlook > Settings > Signatures	No (Local Mac Client)	Rich Text & Images	Yes
Outlook Mobile (iOS/Android)	Profile Avatar > Settings Gear > Signature	No (App-Level Storage)	Plain Text Only	One per Account

How do you change your signature in Classic Outlook for Windows?

Classic Outlook for Windows (included with Microsoft 365 desktop apps as well as Outlook 2021, 2019, and 2016) manages email sign-offs through a dedicated preferences window. It saves template files locally on your storage drive while synchronizing default preferences with connected Exchange mailboxes.

Steps to create or edit a signature in Classic Outlook

1. Launch the Classic Outlook application on your Windows computer.
2. Click File in the top-left menu bar, then select Options near the bottom of the left sidebar.
3. In the Outlook Options window, click Mail in the left column menu.
4. Under the Compose messages section, click the Signatures… button to open the Signatures and Stationery dialog box.
5. Select an existing signature name from the list under Select signature to edit, or click New, type a descriptive name, and click OK.
6. Type your text and contact details into the Edit signature text box. Use the formatting toolbar to modify font styles, sizes, text alignments, or color palettes.
7. To add an image or company logo, click the picture icon on the right edge of the formatting toolbar, select your graphics file, and click Insert.
8. Assign your signature under the Choose default signature section on the right. Select your email address from the E-mail account dropdown.
9. Select your signature from the New messages dropdown menu. Select your preferred signature (or (none)) from the Replies/forwards dropdown menu.
10. Click OK on the Signatures and Stationery window, then click OK on the main Outlook Options window to apply changes.

You can also access signature options directly from any active message composition window. Click New Email on the Home ribbon tab, click Signature in the message ribbon toolbar, and choose Signatures… from the pop-up menu.

Editing signature template files on your computer

Classic Outlook generates three distinct files for every signature you build: an HTML file (.htm), a Rich Text file (.rtf), and a Plain Text file (.txt). If you need to edit signature markup directly using HTML code, you can open the underlying system folder on Windows:

1. Press Win + R on your keyboard to launch the Run command box.
2. Type %appdata%MicrosoftSignatures into the text field and press Enter.
3. Right-click the .htm file matching your signature name and select Open with > Notepad (or your preferred code editor).
4. Make your code adjustments, save the file, and close the text editor. The updated code will render immediately inside Outlook.

How do you change your signature in the New Outlook for Windows?

The New Outlook app for Windows replaces the traditional Win32 architecture with a web-based client engine. Because of this design, its settings interface mirrors the Microsoft 365 web portal.

1. Open the New Outlook application on Windows.
2. Click the Settings gear icon located in the upper-right corner of the top app bar.
3. Select Accounts from the left sidebar menu, then click Signatures in the middle panel.
4. Click + New signature.
5. Type a unique identifier name for your signature in the top input box.
6. Compose your layout in the lower text editing canvas. Use the toolbar at the bottom of the editor to adjust fonts, insert hyperlinks, add inline tables, or attach image files.
7. Scroll down to the Select default signatures heading. Choose which signature auto-populates For new messages and which auto-populates For replies/forwards.
8. Click Save at the bottom of the settings pane to commit your changes.

How do you change your signature in Outlook Web?

When working through a browser at Outlook.com or an organizational Microsoft 365 web portal, your signature settings are maintained directly on the cloud server.

Steps for updating signature settings on the web

1. Navigate to Outlook.com or your company’s Microsoft 365 sign-in page and log in to your mail account.
2. Click the Settings gear icon situated in the top-right header toolbar.
3. Select Mail from the far-left navigation column, then click Compose and reply in the center column.
4. Locate the Email signature section. Click + New signature or choose an existing entry from the signature list to make edits.
5. Input your sign-off details, job titles, phone numbers, and web links into the editor frame. Use the formatting controls at the base of the frame to adjust styling or insert graphics.
6. Under Select default signatures, choose your default selections for For new messages and For replies/forwards.
7. Click Save at the bottom of the options window.

Modifications saved in Outlook Web apply instantly across all web browsers and sync across desktop clients connected through Microsoft Cloud Signatures.

How do you change your signature in Outlook for Mac?

Outlook for Mac utilizes native macOS preference windows and application menus to manage signature profiles across configured email accounts.

1. Open the Outlook application on your Mac.
2. Click Outlook in the Apple menu bar at the very top of your screen and select Settings… (or Preferences… on older macOS versions). You can also press Command + , on your keyboard.
3. Click Signatures under the Email section of the settings window.
4. Click the + (plus) button beneath the left signature column to add a new signature item, or highlight an existing template to edit it.
5. Double-click the default name (such as Untitled) in the left column to give your signature a recognizable label.
6. Design your layout in the right-hand editor pane. You can adjust font formatting, insert hyperlinks, and drag graphic files directly into the editing field.
7. At the bottom of the window under Choose default signature, pick your target account from the Account dropdown.
8. Select your signature choices from the New messages dropdown and Replies/forwards dropdown.
9. Close the Signatures preferences window to save your settings.

How do you change your signature on Outlook Mobile for iOS and Android?

The official Outlook mobile app on iPhone, iPad, and Android devices handles signatures independently from desktop clients. Mobile signatures are plain-text string entries designed to keep mobile outgoing message sizes small.

1. Open the Outlook app on your smartphone or tablet.
2. Tap your account avatar icon located in the upper-left corner to display the side drawer menu.
3. Tap the Settings gear icon located at the lower-left corner of the panel.
4. Scroll down to the Mail header and select Signature.
5. If you operate multiple email accounts within the app, enable the Per Account Signatures toggle switch to customize each account individually.
6. Tap inside the text field for your selected email account, type or paste your signature text, and tap the back arrow or top checkmark button to save.

Because Outlook Mobile does not support inline HTML images or custom table structures, formatting should rely on plain text, clean line breaks, and explicit web links (such as https://example.com). Receiving mail applications automatically convert full web URLs into clickable hyperlinks.

How do Microsoft Cloud Signatures affect signature synchronization?

Microsoft 365 uses a feature called Cloud Signatures (roaming signatures) across Exchange Online mailboxes. When Cloud Signatures is enabled, any signature you create or update inside Outlook Web or New Outlook automatically syncs to your profile in Classic Outlook on Windows.

This means you do not need to manually export signature files or copy markup when configuring a new desktop computer. Setting default signatures on one supported device applies those defaults across all connected clients signed into that same Microsoft 365 account.

Disabling Cloud Signatures via the Windows Registry

Some users and enterprise IT administrators prefer storing signatures locally on desktop hard drives—for example, when using local automation scripts or specialized add-ins. You can disable cloud signature roaming on a Windows PC by adding a registry key:

1. Close Classic Outlook completely.
2. Press Win + R, type regedit, and press Enter to launch the Windows Registry Editor.
3. Navigate through the left folder tree to: HKEY_CURRENT_USERSoftwareMicrosoftOffice16.0OutlookSetup
4. Right-click on the Setup folder key, highlight New, and click DWORD (32-bit) Value.
5. Enter DisableRoamingSignaturesTemporaryToggle as the value name.
6. Double-click the new item, change its Value data from 0 to 1, and click OK.
7. Reopen Classic Outlook. The application will resume reading and writing signature files exclusively from %appdata%MicrosoftSignatures.

How do you format an Outlook signature without layout errors?

Classic Outlook on Windows uses the rendering engine from Microsoft Word to parse HTML email content rather than standard web engines like WebKit or Blink. Word’s layout engine handles web code strictly, which can cause misaligned graphics, unwanted gaps, or giant image scaling if signature code is built incorrectly.

Essential design and HTML rules for Outlook

• Define explicit pixel sizes for images: Always specify physical width and height attributes within image tags, such as <img src="logo.png" width="150" height="50" alt="Company Logo">. Avoid relying on CSS rules like max-width: 100%, because the Word rendering engine ignores maximum width declarations.
• Control image DPI resolution: Save image files at 96 DPI (dots per inch). High-DPI images (such as 300 DPI retina images) often expand to double or quadruple their size in Classic Outlook unless explicitly restricted by HTML width and height attributes.
• Structure content with simple HTML tables: Build multi-column layouts using standard nested <table> tags with explicit pixel column widths. Modern CSS layouts like flexbox or grid are unsupported in Outlook email views.
• Use universal font families: Choose standard system fonts such as Arial, Calibri, Georgia, Tahoma, Trebuchet MS, or Verdana. If you specify custom web fonts, always supply a standard fallback font (for example, font-family: 'CustomFont', Arial, sans-serif;).
• Host images on public web servers: Rather than embedding local image files directly into the signature box, host logo files on a secure public web server (HTTPS) and link to them using full image URLs. This prevents email file sizes from expanding and reduces the risk of images converting into attachments.
• Use single line breaks: Pressing Enter inside Outlook signature text boxes creates a new paragraph block (<p> tag) with double vertical spacing. Press Shift + Enter to insert a line break (<br> tag) for clean single-spaced text lines.

Troubleshooting common Outlook signature issues

When email signatures distort, lose formatting, or fail to attach automatically, use these proven fixes to resolve the problem.

Signature settings button is grayed out or unclickable

If the Signatures button under Outlook Options is grayed out or changes revert immediately upon restarting, your corporate IT administrator has likely implemented a central Group Policy or Exchange transport policy. Organizations often manage email disclaimers centrally through enterprise tools (such as Exclaimer or CodeTwo) to ensure company-wide legal compliance, disabling manual user editing in local Outlook clients.

Signature images appear as broken attachments or red X icons

If message recipients see a missing image box with a red “X” icon, Outlook’s trust settings or local image paths are blocking graphics. To resolve this in Classic Outlook:

1. Go to File > Options > Trust Center.
2. Click Trust Center Settings… and select Automatic Download.
3. Ensure “Don’t download pictures automatically in HTML e-mail messages or RSS items” matches your administrative network permissions.
4. When using locally embedded images, re-insert them through the Signatures dialog window picture tool rather than copy-pasting image graphics directly from web pages or external documents.

Signature disappears when replying or forwarding emails

If your signature populates correctly when composing new emails but disappears when replying, check your default options in the Signatures menu. Verify that the Replies/forwards dropdown is set to your preferred signature name rather than (none).

Additionally, if you reply to an incoming message sent in Plain Text format, Outlook converts your reply to Plain Text. This strips all HTML formatting, tables, and images from your sign-off. To restore formatting, switch your outgoing message format back to HTML by clicking Format Text in the message top bar and choosing HTML.

Extra vertical gaps between lines of text

When drafting text inside the Outlook signature editor, hitting the Enter key creates an HTML paragraph block that adds blank space below the line. To fix existing double-spaced text, delete the spacing, hold down the Shift key, and press Enter to create a single-line soft break.

Frequently Asked Questions

Can I have multiple signatures in Outlook?

Yes, Outlook allows you to create and save multiple signatures. You can then choose which signature to use for new messages and which for replies or forwards, enabling different signatures for different contexts.

How do I add a logo to my Outlook signature?

In the ‘Signatures and Stationery’ settings, use the ‘Insert Picture’ or image icon within the rich text editor. Ensure the image file is small in size and dimension for optimal rendering across email clients.

Why is my Outlook signature not showing up?

This usually happens if the default signature setting is incorrect for the message type or email account. Revisit the ‘Signatures and Stationery’ settings and verify that the correct signature is selected for ‘New messages’ and/or ‘Replies/forwards’.

Can I use different signatures for different email accounts?

辦Yes. If you manage multiple email accounts in Outlook, you can assign a unique default signature to each individual account through the signature settings panel.

Is there a limit to signature length in Outlook?

While Outlook does not set a strict character limit, long signatures with heavy image files can cause message rendering issues or be truncated by receiving mail servers. Aim for a concise format containing essential contact information.

How to change signature on Outlook Web App?

Access Outlook Web settings via the gear icon, then navigate to Mail > Compose and reply. You will find the email signature editor and default settings there to customize your signature.

Source: Britannica.