Sign your name · Manual

Sign your name is an editor for Apple Mail email signatures. The app lets you edit signatures directly as HTML and protect them from being overwritten by Apple Mail.

1. Setting up permissions

Sign your name reads and writes signature files in the folder ~/Library/Mail/V*/MailData/Signatures/. This folder is protected by macOS. On first launch the app will display an error message.

To grant the required permission:

1. Open System Settings (or click the button in the app's error dialog)
2. Go to Privacy & Security > Full Disk Access
3. Click + and add Sign your name
4. Restart the app

Without this permission the app cannot load or save any signatures.

2. The interface

Sidebar (left)

The sidebar lists all signatures that exist in Apple Mail. Each signature has a lock icon:

• Locked (green) — The file is read-only. Apple Mail cannot overwrite it.
• Unlocked (grey) — The file is writable. Apple Mail may overwrite your custom formatting.

Below the list are + and - buttons to create and delete signatures. When creating a new signature you can choose between HTML and plain text.

Right-clicking a signature opens a context menu with:

• Rename (also available via the Return key)
• Duplicate
• Delete

The Reload button (arrow icon in the toolbar) reloads all signatures from disk.

Editor (right)

The top bar shows the name, file path, and type (HTML or Plain Text) of the selected signature.

To the right are two buttons:

Lock / Unlock

Locks or unlocks the signature file at the filesystem level.

• Lock sets the file to read-only (chmod 444). This prevents Apple Mail from overwriting the signature when you open Mail or change its settings.
• Unlock makes the file writable again (chmod 644) so you can save changes.

Recommended workflow:

1. Click Unlock to make the signature editable
2. Edit the HTML code in the editor
3. Click Save (or Cmd+S)
4. Click Lock to protect the signature again

Save

Saves the current editor content back to the signature file. The button is only enabled when the editor content differs from the saved version. Keyboard shortcut: Cmd+S.

When saving, the file is automatically unlocked briefly, written to, and locked again.

Preview (bottom)

Below the editor a live preview shows the rendered signature. The Copy button (document icon) copies the formatted signature to the clipboard — useful for pasting into Gmail or other email clients.

3. How it works with Apple Mail

Apple Mail stores signatures as .mailsignature files in the folder ~/Library/Mail/V*/MailData/Signatures/. Each file consists of a header block (Content-Type, Message-Id, etc.) followed by the actual HTML body.

The problem: Apple Mail tends to overwrite custom formatting in signature files. When you edit a signature in Mail or Mail refreshes its settings, elaborate HTML signatures get lost.

The solution: Sign your name locks signature files using file permissions. A locked file (green lock icon) cannot be modified by Apple Mail. Your signature stays exactly as you designed it.

Important:

• Signatures you create in Sign your name will appear in Apple Mail only after you restart Mail.
• Conversely, if you create a signature in Apple Mail, click the Reload button in Sign your name to see it.
• Always lock your signatures after editing to prevent Apple Mail from overwriting them.