What signing an email means and why you might do it
Signing an email means adding your name, title, or contact details at the bottom — the part that comes after you finish writing. Most people do this automatically without thinking about it. But "signing" can also mean something more formal: using a digital signature to prove the email came from you and hasn't been changed in transit.
The first kind — a text signature — is what most people need. It's just information you want every email to include. The second kind — a cryptographic signature — is rarer and requires setup through your email provider or a separate tool. This guide covers both, starting with the one you'll actually use.
Key Takeaways
- A text signature is lines of text that appear at the bottom of every email you send, usually containing your name, title, phone number, or company details.
- Most email providers let you create a signature in settings and choose whether it appears on all emails or only replies.
- A digital signature uses encryption to prove an email came from you and wasn't altered — it's different from a text signature and requires setup through your email provider.
- Signatures can include formatting, links, and images, but keep them short so they don't clutter every message you send.
- You can create multiple signatures and choose which one to use for each email, useful if you have different roles or accounts.
How to add a text signature in Gmail
Open Gmail and go to Settings (the gear icon in the top right). Click "See all settings," then find the "Signatures" tab. Click "Create new" and give your signature a name — you can have more than one. Type or paste the text you want to appear at the bottom of your emails.
Below the text box, you'll see options to choose which account this signature applies to (if you have multiple Gmail accounts) and whether it appears on new emails, replies, or both. Most people want it on everything. Click "Save Changes" at the bottom of the page. From now on, that text will appear automatically when you compose a new email.
If you want to include a link or make text bold or italic, highlight the text and use the formatting buttons above the signature box. You can also insert an image by clicking the image icon, though keep images small — they add to email file size.
How to add a text signature in Outlook
In Outlook on the web, click the gear icon in the top right and select "View all Outlook settings." Go to "Mail" and then "Compose and reply." Scroll down to "Email signature" and type or paste your signature text in the box.
Check the box next to "Automatically include my signature on new messages I compose" if you want it on all new emails. If you also want it on replies and forwards, check that box too. Click "Save" at the bottom. The signature will now appear in every email you send from that account.
In Outlook on your desktop (Windows or Mac), go to File, then Options (Windows) or Preferences (Mac). Find "Mail" and then "Signatures." Click "New," name your signature, type the text, and choose whether it applies to new messages, replies, or both. Click "OK" to save.
How to add a text signature in Apple Mail
Open Apple Mail and go to Mail menu, then Preferences. Click the "Signatures" tab. On the left, select the email account you want to add a signature to. Click the plus sign at the bottom to create a new signature, give it a name, and type your text in the box on the right.
Below the signature box, you'll see a dropdown that says "Select signature(s) to use with account." Choose "All Signatures" if you want this one to appear on every email, or leave it blank to choose manually each time you send. Close Preferences and the signature will be ready to use.
How to add a digital signature to prove an email is from you
A digital signature is different from a text signature. It uses encryption to prove the email came from you and wasn't changed after you sent it. The reader sees a small indicator (often a checkmark or lock icon) that the signature is valid. This requires a certificate — a digital file that proves your identity.
In Gmail, you cannot create a digital signature directly. You would need to use a third-party tool like Virtru or send through a service that supports S/MIME (find/Multipurpose Internet Mail Extensions). In Outlook, go to File, Options, Trust Center, Trust Center Settings, then Email Security. Click "Get a Digital ID" to request a certificate from a provider like Sectigo or DigiCert. Once you have it, Outlook will let you sign emails with it.
For most people and most emails, a text signature is enough. Digital signatures are mainly used in legal, financial, or healthcare settings where proving the email's origin and integrity matters legally.
What to include in a signature and what to avoid
A basic signature includes your name, job title, company name, phone number, and email address. Some people add a website, LinkedIn profile, or physical address. Keep it to four or five lines — longer signatures clutter inboxes and slow down email loading, especially if you send many messages.
Avoid including images unless they're small (like a company logo) and necessary. Don't use colored text or unusual fonts that might not display correctly on the reader's device. Never include sensitive information like passwords, account numbers, or personal identification numbers. If your company has a signature template or style guide, follow it — consistency matters in professional settings.
Some people add a legal disclaimer or confidentiality notice. These are common in law firms and financial services. Keep these short too — they're legally required in some industries but should not be longer than the actual message in casual emails.
How to use different signatures for different emails
Most email providers let you create multiple signatures and choose which one to use. In Gmail, create several signatures in Settings and give each a clear name — for example, "Work," "Freelance," or "Personal." When you compose an email, look for a dropdown menu near the bottom that says "Signature" and pick the one you want.
In Outlook, create multiple signatures in the Signatures settings and name them clearly. When composing, go to Insert, Signature, and choose the one you need. You can also set a default signature for each account, then override it on individual emails.
This is useful if you have multiple jobs, run a side business, or manage accounts for different purposes. You can keep a formal signature for client work and a casual one for internal team emails, for example.
Frequently Asked Questions
Can I add a signature to emails I've already sent?
No. A signature is added when you compose and send an email. Once it's sent, you cannot edit it. If you need to correct something, you would have to send a new email or use your email provider's "unsend" feature if it has one — Gmail and Outlook both offer a short window (usually 10 to 30 seconds) to recall an unsent message.
Will my signature appear on emails I forward?
It depends on your settings. Most email providers let you choose whether signatures appear on new emails, replies, forwards, or all three. Check your signature settings and adjust the options to match what you want. Many people turn off signatures on forwards to avoid cluttering a chain of messages.
What if my signature isn't showing up?
First, check that you've enabled the signature in your settings — sometimes it's created but not turned on. Make sure you're composing a new email, not replying, if your settings only explore signatures to new messages. If you're using a mobile app, some apps don't support signatures the same way the web version does. Try composing from a web browser instead.
Can I use HTML code in my signature?
Most email providers support basic HTML in signatures — things like links, bold text, and images. Gmail and Outlook both have formatting buttons in the signature editor. If you want to write HTML directly, some providers have an "HTML" option in the signature settings. Be careful with complex code, as it may not display correctly on all devices or email clients.
Is a digital signature the same as a text signature?
No. A text signature is just information at the bottom of your email. A digital signature uses encryption to prove the email came from you and wasn't changed. Digital signatures are legally binding in some contexts and require a certificate. Most people only need a text signature.