How to Add a Handwritten Signature to Your Email Signature: Outlook, Gmail, Apple Mail

A handwritten signature under an email feels more personal than a typed sign-off, especially on quotes, job applications or in small businesses. Technically it is a small image in your email signature. Here is how big it should be and how to add it in Outlook, Gmail and Apple Mail. And where it does not work.

The right image for an email signature

• Format: PNG with a transparent background, so no white box appears on coloured or dark backgrounds.
• Size: about 200 to 300 pixels wide on screen is enough for the signature alone.
• File size: keep it well under 100 KB. A signature PNG is usually far below that.
• Dark mode: black ink on a transparent background can be hard to see in some apps' dark mode. Send yourself a test email after setting it up and check it in dark mode too.

Outlook

Outlook comes in versions whose menus differ¹.

New Outlook for Windows and Outlook on the web

1. Open Settings (gear) > Accounts > Signatures.
2. Create a new signature and give it a name.
3. Type your sign-off and name, then insert your PNG with the image button in the toolbar above the text box.
4. Choose whether the signature appears on new messages and replies automatically, and save.

Classic Outlook for Windows

1. Open a new email.
2. On the Message tab, click Signature > Signatures.
3. Choose New, enter your text and insert the PNG with the picture button in the editor.
4. On the right, pick the default signature for new messages and replies, then click OK.

Classic Outlook embeds the image in the email, so some recipients see it as an attachment. Keep the image small and it hardly shows.

Gmail

1. Click the gear at the top right, then See all settings.
2. On the General tab, scroll down to Signature and create a new one.
3. Enter your text and insert your image with the image button in the signature editor.
4. At the bottom, click Save Changes².

A Gmail signature can have up to 10,000 characters, and according to Google an image counts towards that limit². A small PNG is therefore better than a large photo.

Apple Mail on a Mac

1. Open Mail > Settings > Signatures.
2. Choose the account on the left and add a signature with the plus button at the bottom.
3. Type your text and drag the PNG from Finder straight into the preview on the right³.
4. Use the menu at the bottom to choose which signature is added automatically.

iPhone and iPad

In the Mail app on an iPhone you set up the signature under Settings > Mail > Signature, in newer iOS versions under Settings > Apps > Mail. It only takes text, though, you cannot insert images. There are workarounds with copy and paste from an email, but they are not reliable.

Is an inserted signature legally binding?

In England and Wales, usually yes. Electronic signatures are admissible in evidence⁴, and the Law Commission concluded in 2019 that an electronic signature can be used to execute a document, provided the person signing intends to authenticate it and any other formalities are met⁵. It lists scanned handwritten signatures among the types of electronic signature.

The exceptions are the documents with extra formalities:

• Deeds: they must be signed in the physical presence of a witness, even when both use electronic signatures⁵.
• Wills: a will must be signed or acknowledged in the presence of two witnesses present at the same time⁶. A pasted image is not a safe way to sign one.
• Anyone asking for a wet signature: banks, landlords or government forms can insist on an original signed in ink.

EU eIDAS rules, kept in UK law, add that an electronic signature cannot be refused just because it is electronic, and that only a qualified electronic signature has the same effect as a handwritten one⁷. An inserted signature image is a simple electronic signature. Your typed name at the bottom of an email can already count as a signature. The image makes it more personal, not more binding.

Important: A digitised signature is not a qualified electronic signature. If in doubt, ask whoever receives the document whether they accept it. This article is not legal advice.

Frequently asked questions

How big should a signature be in an email signature?

About 200 to 300 pixels wide on screen and well under 100 KB. A PNG with a transparent background adapts to any background.

Why does my signature show up as an attachment?

Some apps, such as classic Outlook, embed images in the email. Some recipients' apps then also show those images as attachments. A small image is less noticeable.

Can I add a signature image on my iPhone?

Not reliably in Apple's Mail app. The signature setting on the iPhone is meant for text.

Is an email with an inserted signature legally binding?

Under English law an email can be signed electronically, even your typed name can count, as long as you intend to sign. Deeds and wills have extra formalities, and there an email or a signature image is not enough.

Sources

1. 1Microsoft: Create and add an email signature in Outlook (support.microsoft.com)
2. 2Gmail Help: Create a Gmail signature (support.google.com)
3. 3Apple: Create and use email signatures in Mail on Mac (support.apple.com)
4. 4Electronic Communications Act 2000, section 7 (legislation.gov.uk)
5. 5Law Commission: Electronic execution of documents (Law Com No 386, 2019) (lawcom.gov.uk)
6. 6Wills Act 1837, section 9 (legislation.gov.uk)
7. 7Regulation (EU) No 910/2014 (eIDAS) as retained in UK law, Article 25 (legislation.gov.uk)