How to add an email signature in Proton Mail

Before you start: have the signature ready

Proton's signature editor is rich text with an insert image button that takes a URL. Build the signature first, with the logo hosted on your website, and paste it in. The free signature generator does this with Copy signature and the link to a logo option.

Proton Mail on the web

1. Copy your signature.
2. Click Settings (gear, top right), then All settings.
3. Open Identity and addresses.
4. Under Display name and signature, pick the address if you have several.
5. Click into the signature editor and paste. Use the toolbar's image button to add or replace a logo by URL.
6. Click Update.

The signature is added to new messages, replies and forwards. Proton places it above the quoted text on replies.

Proton Mail on iPhone and Android

1. Open the menu, then Settings.
2. Tap the account, then Mobile signature (Android) or Signature (iOS).
3. Turn it on and type the text.

The mobile signature is plain text and is used instead of the web signature when you send from the app. There is also a separate Sent from Proton Mail mobile line you can turn off. The web signature applies only to mail sent from the browser.

On the free plan

Free accounts can set a signature but cannot remove the Sent with Proton Mail secure email footer, which is appended after it. Paid plans (Mail Plus and above) turn the footer off under the same settings page.

Using Outlook, Apple Mail or Thunderbird through Proton Mail Bridge

Bridge presents your Proton account to a desktop client as IMAP/SMTP. The client, not Proton, adds the signature, so set it where that client keeps it: the Outlook, Apple Mail or Thunderbird guide has the steps. Leave the Proton web signature empty, or it is added twice.

Common problems

The logo is blank for recipients

Proton loads remote images for you only if you have allowed them, and the same is true for the people you write to. A hosted logo is still the right choice; just expect some recipients to see it only after they click load images.

Formatting was lost when pasting

Proton keeps inline styles, links and tables and strips scripts, stylesheets and most CSS classes. If the result looks plain, the source relied on a stylesheet. Re-copy from a signature that follows the HTML best practices.

Different signature on my phone

The apps use the mobile signature, not the web one. Set both, or keep the mobile one short on purpose.

Setting signatures for a whole company

Proton for Business lets an admin manage users but each person still sets their own signature. If consistent signatures matter more than end-to-end encryption between colleagues, the usual path is mail on Microsoft 365 or Google Workspace with UnifySig applying one policy server-side.