How to add an email signature in Apple Mail, Thunderbird, Google Workspace and Microsoft 365

You have generated a clean signature with our free email signature tool. Now comes the step that often trips people up: installing it in your email client. Each client has its own logic, and a bad copy-paste is enough to break the formatting. This guide walks you through the reliable method for the four most common environments: Apple Mail, Thunderbird, Google Workspace (Gmail) and Microsoft 365 (Outlook).

First: get your signature from the tool

On the last step (Export) of the tool, you have two options:

• "Copy signature": copies the formatted version, ready to paste straight into your email client's signature field. This is the preferred method for Gmail, Outlook and Apple Mail.
• "Download all (ZIP)": downloads one .html file per team member. Useful for Thunderbird (signature from a file) and for the advanced Apple Mail method.

If you have several team members, pick the right person from the dropdown before copying.

The image trap. In an email, a logo or banner must be hosted at a public web address (an https://… URL). A "pasted" or locally-stored image will not show up for your recipients. Our tool offers an image hosting option that handles this automatically.

Apple Mail (macOS)

Apple Mail is the fussiest: it happily rewrites your formatting. The reliable method:

1. Open Mail → Settings (or Preferences) → Signatures tab.
2. Select the relevant account in the left column, then click "+" to create a signature. Give it a name and type any placeholder text in the right pane.
3. Uncheck "Always match my default message font", otherwise Mail overrides your signature's styling.
4. In the tool, click "Copy signature". Back in Mail, click in the right-hand edit area, select all (Cmd + A) and paste (Cmd + V).
5. Close the settings window. Open a new message to check the result.

If pasting breaks the formatting (advanced method):

1. First create a placeholder signature in Mail (to generate the file), then quit Mail completely.
2. Open the ~/Library/Mail/V*/MailData/Signatures/ folder and find the matching .mailsignature file (open them to spot your placeholder text).
3. Replace the HTML block (after the few header lines at the top of the file) with the contents of the .html file from the ZIP, then save.
4. Lock the file: select it in Finder → Get Info (Cmd + I) → tick "Locked". Without this lock, Mail rewrites the file when it reopens and your signature is lost.
5. Reopen Mail.

On iPhone / iPad, the Mail app does not support rich HTML signatures: keep a simple text version there, and keep the full signature on your Mac.

Thunderbird

Thunderbird handles HTML very well, with two possible methods.

Simple and robust (file) method:

1. Menu ☰ → Account Settings.
2. Select the account in the left column.
3. Tick "Attach the signature from a file instead", then "Choose…" and point to the .html file extracted from the ZIP.

This is the most faithful, and you only need to replace the file to update the signature everywhere.

Paste-the-code method:

1. Still in Account Settings, tick "Use HTML" under the Signature text field.
2. Open the ZIP's .html file in a text editor, copy all the code, and paste it into the field.

Google Workspace (Gmail)

1. In Gmail, click the gear icon → "See all settings".
2. "General" tab → scroll to the "Signature" section → "Create new".
3. Name the signature, click in the edit area, then paste (Cmd/Ctrl + V) the signature copied from the tool.
4. Just below, set it as the default for new emails and replies.
5. Scroll to the bottom of the page and click "Save changes".

For the whole organization (Google Workspace admin): the admin console can append a common footer (Apps → Google Workspace → Gmail → Compliance → Append footer). But for rich individual signatures (photo, logo, each person's own details), pasting per user remains the most faithful method.

Microsoft 365 (Outlook)

The location depends on your Outlook version.

Outlook on the web / "new Outlook":

1. Settings (gear icon) → Mail → Compose and reply.
2. "Email signature" section → paste your signature, name it.
3. Set it as the default for new messages and replies, then Save.

Classic Outlook (Windows): File → Options → Mail → Signatures → "New", paste into the edit area, then OK.

Outlook for Mac: Outlook → Settings → Signatures → "+", then paste.

For the whole organization (Microsoft 365 admin): the Exchange admin center can append a common disclaimer / footer (Mail flow → Rules → Apply disclaimers). Note: this footer is added at the bottom of the message and does not appear in the sender's Sent Items; for a perfect result, prefer the signature configured by each user.

Troubleshooting: the most common issues

• Images don't show up → they must be hosted at a public URL. Use the tool's image hosting option, or point the logo and banner to accessible https:// addresses.
• Formatting breaks on paste → never "clean up" the formatting after pasting, and avoid routing it through Word or an intermediate editor. Paste directly from the clipboard.
• Extra spaces or line breaks → usually caused by a client adding its own margin; in most cases it is not visible to the recipient.
• The signature doesn't appear on mobile → mobile apps manage their own signature; reconfigure it from the app itself.

Create, then install in minutes

A polished signature only matters if it is installed everywhere, identically, for the whole team. Our free signature generator produces HTML that is compatible with Gmail, Outlook and Apple Mail, and the CSV export lets you generate signatures for an entire team at once.

→ Create my email signature for free

To understand what makes a good signature (content, design, compatibility), read our professional email signature guide. And if you want a consistent identity beyond the signature (logo, colours, website), let's talk about your project or explore our approach to brand identity.