How to Add a Signature to an Email: Gmail, Outlook, Apple Mail, Yahoo, Thunderbird and Android

To add a signature to an email, open your email app's settings, find the Signature section, type or paste your signature and save it. From then on, the app adds it to every new email automatically. The exact place depends on the app: in Gmail on a computer it's Settings > See all settings > General > Signature, in new Outlook it's Settings > Accounts > Signatures, and on an iPhone it's Settings > Apps > Mail > Signature.

Below are the steps for every common email app as of October 2026, checked against each vendor's own help pages.

Looking to e-sign a document (a PDF or a contract)? That's a different task. An email signature is the block of contact details at the bottom of your emails: name, job title, phone number, maybe a logo. Signing a document means adding your legally binding signature to a file, which you do in an e-signature app or in a PDF reader, not in your email settings. And a digital signature in email (S/MIME) is a security certificate that proves a message came from you, usually set up by an IT team, not a block of text.

Which email app are you using?

Each app keeps its own signature, and a signature set in one app doesn't carry over to another.

Step 1: create the signature once

For a name and a phone number, the app's own signature box is enough. For a logo, brand colors or social icons, design the signature once outside your email app and paste the finished version into each app you use.

You can make one in a few minutes with Signguin, a free email signature generator. Type your work email and it loads your company logo, brand colors and contact details from your website. The result is email-safe HTML with hosted images, built to hold together in Outlook, Gmail and Apple Mail, and the free plan needs no sign-up. Penguins are born in a tuxedo; the rest of us need a minute or two.

Prefer plain text? Our professional email signature guide covers what to include.

Gmail signature

On a computer: click the Settings gear at the top right, then See all settings. On the General tab, scroll down to Signature, click Create new (or click an existing signature), type or paste it in the box, pick it under Signature defaults, and click Save Changes at the bottom of the page. Gmail allows up to 10,000 characters per signature.

Gmail app on iPhone or iPad: tap Menu at the top left, then Settings, then Signature settings under "Compose and Reply". Turn on Mobile Signature, type it, and tap Back to save.

Our Gmail signature guide covers logos, reply signatures, "Send mail as" addresses and the "signature too long" error.

Gmail app on Android

1. Open the Gmail app.
2. Tap Menu at the top left.
3. Scroll to the bottom and tap Settings.
4. Choose the Google account you want a signature for.
5. Tap Mobile signature.
6. Type your signature and tap OK.

Google's help page adds a useful detail: if you don't create a signature in the Gmail app, new messages use the signature you set up on your computer. To keep your full desktop signature, logo included, on emails from your phone, leave the mobile signature empty, then send yourself a test.

Outlook signature on a computer

Each version of Outlook has its own path. Not sure which one you have? Our Outlook signature guide shows how to tell.

• New Outlook for Windows: Settings (gear icon) > Accounts > Signatures, then Add signature, type or paste, choose whether it goes on new messages and on replies, and Save.
• Outlook on the web (outlook.com, outlook.office.com): the same path, Settings > Accounts > Signatures.
• Classic Outlook for Windows: open a new email, then Message > Signature > Signatures. You can also reach it through File > Options > Mail > Signatures.
• Outlook for Mac: Outlook > Settings > Signatures.

Our Outlook signature guide walks through each version, plus logos and signatures that sync between PCs. If your signature breaks for recipients, see Outlook signature not showing.

Outlook app signature on iPhone and Android

In the Outlook app, tap your profile picture (or account icon) at the top left, tap the Settings gear, then Signature under Mail. Delete the default "Get Outlook for iOS" or "Get Outlook for Android" line, type your signature and go back to save. With several accounts, turn on Per Account Signature to give each one its own.

Your desktop Outlook signature doesn't sync to the app. Our Outlook mobile signature guide explains what the app can show.

Apple Mail signature on iPhone and iPad

Open the Settings app (not the Mail app), tap Apps, then Mail, then Signature under Composing. Replace "Sent from my iPhone" with your signature and tap back. On iOS 17 or earlier, there is no Apps step: go to Settings > Mail > Signature. Tap Per Account to give a work and a personal account different signatures.

Apple's guide says only text can be used. Our iPhone email signature guide covers the iPad and the unofficial copy-and-paste method for a logo.

Apple Mail signature on Mac

1. Open Mail, then choose Mail > Settings in the menu bar and click Signatures. On macOS Monterey and earlier, it's Mail > Preferences > Signatures.
2. In the left column, select the email account the signature is for.
3. Click the Add (+) button below the middle column and type a name for the signature.
4. In the right column, type or paste your signature. The Format menu changes font, color and alignment, the Edit menu turns text into links, and you can drag an image into the preview area.
5. Use the Choose Signature pop-up to pick the signature that is added automatically for that account.
6. Close the Settings window.

Two checkboxes on that screen matter. Untick Always match my default message font for a designed signature, or Mail replaces your fonts with the default message font. Tick Place signature above quoted text to put the signature right under your reply. And a signature created under All Signatures isn't attached to any account until you drag it onto one. To delete a signature, select it and click the minus (-) button.

Yahoo Mail signature

Yahoo Mail on a computer

1. Open Yahoo Mail in your browser.
2. Click the More options icon, then select Settings.
3. Click Writing email.
4. Click the toggle next to the email address to turn its signature on.
5. Type or paste your signature in the text box.

Turn the toggle off to stop using it. Every address you added to your Yahoo account, from any provider, gets its own signature here. In the older Yahoo Mail design, the path is the Settings icon > More Settings > Writing email.

Yahoo's help page calls the signature area a text box and says nothing about logos or formatting, so if you paste a designed signature, send yourself a test email.

Yahoo Mail app on iPhone

1. Tap the Menu icon.
2. Tap Settings.
3. Tap Signatures under General.
4. Tap the toggle to turn the signature on.
5. Tap below each username and type your signature.
6. Tap the back arrow at the top left to save.

Yahoo Mail app on Android

1. Tap the Menu icon, then Settings.
2. Tap Signatures under General.
3. Turn on Include signature in new messages.
4. Tap below it and type your signature.
5. Tap the back arrow at the top left to save.

For a different signature per account on Android, turn on Customize for each account in step 3, tap the account, then turn on Include signature in new messages for it.

Thunderbird signature

Thunderbird keeps one signature per account, set in Account Settings.

1. Click the menu button and choose Account Settings. With the menu bar showing, it's Tools > Account Settings (on Linux, Edit > Account Settings).
2. In the left panel, select the account the signature is for.
3. Type your signature in the Signature text field.
4. If you have more than one account, repeat for each one: Mozilla notes that signatures are configured separately per account.

Thunderbird handles designed signatures differently from most apps: the Signature text field takes HTML code, not a pasted, formatted signature. You have two options:

• Use HTML: tick Use HTML and paste the HTML source of your signature into the Signature text field. In Signguin, the Copy HTML code button gives you exactly that.
• Signature from a file: tick Attach the signature from a file instead, click Choose... and select an HTML file containing your signature. You can make that file in Thunderbird itself: write the signature in a new HTML message, then File > Save As > File, saved as an HTML file. To add a logo while you compose it, use Insert > Image.

Signature under your reply: by default, Thunderbird puts the signature below the quoted text in replies. To move it, go to Account Settings > your account > Composition & Addressing, set the reply style to Start my reply above the quote, then set and place my signature to below my reply (above the quote).

Samsung Email and other Android apps

Most Android phones use the Gmail app (steps above). Galaxy phones also ship with Samsung Email. We couldn't find an official Samsung help page documenting its signature steps as of October 2026, so we won't give you a click path we haven't verified: open the app's settings, look for a Signature option under your email account, then send yourself a test. The same goes for any other phone email app: the signature lives in that app's own settings, separate from your computer's.

Pasting a designed signature: what each app accepts

Most "my signature looks wrong" problems start here, because each app takes a designed signature differently:

The common thread: copy the signature as you see it, not the code, for every app except Thunderbird. Images should be hosted online and linked, not inserted from your computer, or they tend to arrive as attachments. Our email signature size guide has pixel sizes for logos and icons, and our email signature templates show layouts that hold up in these apps.

Signguin hosts the images for you and gives step-by-step copy-and-paste instructions for Outlook, Apple Mail and other apps. For Gmail you can also install the signature straight into Gmail: you connect Gmail once, and Signguin only asks permission to change Gmail settings, never reads your email and doesn't keep access.

Why your phone sends a different signature

Your signature belongs to the app, not to your email address. Read the same work account in Outlook on your PC, the Gmail app on your phone and Apple Mail on your iPad, and you have three signatures to set up, and three to update when your phone number changes.

Two partial exceptions: the Gmail app falls back to your computer signature when the mobile one is empty, and with a Microsoft 365 or Outlook.com mailbox, Outlook for Windows signatures roam between your PCs. They don't reach the Outlook phone app, which a Microsoft Q&A answer from November 2025 confirms.

A practical setup: a full designed signature on your computer and a three- or four-line text version (name, title, phone, website) on your phone, with the same details in the same order.

Test your signature before you rely on it

1. Send yourself a new email and a reply, and check that the right signature appears on each.
2. Send one to an address in a different app (say, from Outlook to Gmail) and open it on a phone too.
3. Check that the logo loads and doesn't arrive as an attachment, and click every link.
4. Repeat on every device you send from.

FAQ

How do I put a signature on an email automatically?

Set it up once in your email app's signature settings and choose it as the default for new messages: Signature defaults in Gmail, the new messages and replies options in Outlook, the Choose Signature pop-up in Apple Mail on the Mac. After that, the app adds it to every new email by itself.

How do I add a signature in Yahoo Mail?

On a computer, click the More options icon, select Settings, then Writing email. Turn on the toggle next to your email address and type your signature in the text box. In the Yahoo Mail app, go to Menu > Settings > Signatures, switch the signature on and type it. Each address in your account can have its own signature.

Can I add a logo or image to my email signature?

Yes in most desktop apps: Gmail, Outlook, Apple Mail on the Mac and Thunderbird all accept images in signatures. Phone apps are mostly text only. Use a small PNG or JPG hosted online rather than a file from your computer, so it doesn't turn into an attachment. A signature generator handles the hosting and sizing for you.

Why doesn't my signature show up on emails from my phone?

Because each app has its own signature. A signature set in Outlook or Gmail on your computer doesn't appear in Apple Mail or the Outlook app on your phone. Open the settings of the app you actually send from on your phone and add the signature there. The Gmail app is the exception: it uses your computer signature when no mobile signature is set.

Is an email signature the same as an electronic signature?

No. An email signature is the contact block at the end of your messages. An electronic signature is how you sign a document, such as a contract or PDF, and is done in an e-signature or PDF app. A digital signature (S/MIME) is a certificate that proves who sent an email, usually set up by an IT team rather than in your signature settings.