How to add an email signature in Proton Mail
Create a Proton Mail signature for each address, paste a formatted BrandSig design, manage the separate mobile footer and fix missing images.
Proton Mail lets every sending address have its own display name and signature. That is useful for people who use a personal address, a custom-domain address and aliases from the same inbox. The less obvious part is that Proton's mobile apps can add a second, separate mobile footer.
This guide covers the current web and mobile settings, formatted signatures, remote images and the difference between a regular signature and the Proton mobile line.
Proton Mail signature settings at a glance
| Task | Setting | What matters |
|---|---|---|
| Create a regular signature | Settings > All settings > Identity and addresses | Select the correct email address first |
| Format or paste a design | Display name and signature editor | Remote images depend on the recipient's settings |
| Change it for one email | Message composer | The default can be edited or removed per message |
| Edit the mobile footer | Mobile app > Settings > Signature | Editing or disabling it requires a paid plan |
Proton's official signature guide confirms that signatures are stored per address and that formatted content from a third-party builder can be pasted into the editor.
Add a signature in Proton Mail on the web
- Sign in at Proton Mail and open Settings.
- Choose All settings.
- Open Identity and addresses.
- Scroll to Display name and signature.
- If you have several addresses, choose the address you want to edit.
- Enter or paste the signature and click Update.
Open a new message from that same address to verify the result. Proton adds the saved version by default, but you can change or remove it in an individual draft without changing the stored signature.
Use a different signature for each address
The address selector is the most important control in this workflow. A signature belongs to a sending address, not simply to the whole account. Choose each address in turn and give it the correct version.
A practical setup is a full professional signature for your custom domain, a compact version for replies from your primary address and a minimal name-only version for aliases used for private accounts. Keep the identity consistent with the From address: a company logo beneath an unrelated alias creates more suspicion than trust.
If the wrong signature appears, check which From address is active in the composer before editing the design.
Paste a BrandSig signature
Build the signature in BrandSig, copy the rendered result and paste it into Proton's signature field. Proton explicitly supports importing formatted signatures from third-party builders as either formatted text or code.
Use real text for your name, role and contact details. Add a logo as a supporting image rather than turning the whole signature into one picture. This preserves readable contact information when remote content is blocked and keeps phone numbers and links useful.
After pasting, click Update, compose a fresh email and send it to another provider. The saved editor preview is not a substitute for a delivered-message test.
Add a logo or image
The editor toolbar can add images, text styles, colors, lists and links. Proton notes that recipients must allow remote content to see remotely hosted images. That means the signature should still make sense when the logo is absent.
Use a public HTTPS image URL, fixed display dimensions and useful alternative text. Avoid a private cloud link that needs a login. Open the direct image address in a private browser window; it should show only the image.
The HTML versus image signature guide explains why one large PNG is a fragile replacement for a compact HTML layout.
Understand the separate mobile signature
Proton's iOS and Android apps add a mobile line that is separate from the regular address signature. By default it says that the message was sent from Proton Mail mobile.
Open the Proton Mail app and go to Menu > Settings > Signature > Mobile signature. On a paid plan, you can edit the text or disable the toggle. Proton's mobile signature documentation says free accounts cannot edit or disable this mobile footer, although they can still create a regular custom signature.
If both versions are enabled, a message can contain your professional signature and the mobile line. Send a phone test before deciding the regular signature is duplicated.
Why the signature is missing or looks wrong
Nothing appears in a new draft. Confirm that you saved with Update and selected the same sending address in the composer.
The wrong identity appears. Edit the signature attached to the active From address. Each Proton address can store a different version.
The logo is blank. The recipient may block remote content, or the image URL may not be public. Keep essential details as text.
Two sign-offs appear on mobile. One is the regular address signature and the other is the mobile footer. Disable or shorten the mobile version if your plan allows it.
Formatting changes after paste. Simplify the design to tables, inline styles and common fonts. Follow the signature rendering standards rather than modern webpage CSS.
Test privacy and presentation together
Send from every address you use to Gmail, Outlook and a phone. Check the From identity, visible links, image behavior with remote content blocked and the final mobile footer. Proton protects message content, but an email signature is intentionally public information attached to outgoing mail. Include only the phone number, address and social profiles you actually want every recipient to receive.
A good Proton setup is simple: one deliberate signature per sending address, a separate decision about the mobile line and a design that remains useful without remote images.