You can keep up to 20 signatures, each with its own name, and mark one of them as your default. The default is the one added automatically when you write.

If the mailbox you connected already keeps a signature, you can bring it in with one click. Click Import from your inbox, next to Add a signature on the signatures page, or next to Create signature in Email settings under Composing when you have no signature yet. While it looks, the link reads Reading your inbox….

• When one of your addresses has a signature, the editor opens with it already in place, named after that address, exactly as if you had pasted it. If another of your mailboxes could not be read, that one signature is listed instead, with the line saying why under it, and Import opens it.
• When several do, for example your own mailbox, another address you send from, or an outreach mailbox of yours, each one is listed with a preview. Click Import on the one you want.

Nothing is saved until you click Create signature, so you can rename it or change it first. The import only reads: the signature kept in your mailbox is left exactly as it is, and changing the copy here does not change it there.

If the import cannot bring anything in, it says why in one line:

• “Your inbox has no signature set yet.” None of your addresses has one, so write one yourself instead.
• “Could not read the signature from your address. Reconnect it in Integrations.” That mailbox needs you to sign in to it again.
• “Could not read the signature from your address. Try again in a moment.” That one mailbox could not be read this time; the others are still shown.
• “Could not read your inbox right now. Try again in a moment.” Nothing could be read this time.

Make default on the signatures page and the Default signature picker in Email settings both choose which signature is added for you. Exactly one signature is your default at a time. If you set them to different signatures, the Email settings picker is the one that wins.

To stop signatures being added automatically, open Email settings, go to Composing, and set Default signature to No default signature. Nothing is added to new messages, replies or forwards from then on, including any signature you had before you started using this page.

Your saved signatures are untouched and you can still insert one by hand while writing. Pick a signature in the same place to turn automatic signatures back on. Creating a signature counts as picking one: it becomes your default and turns automatic signatures back on, because creating a signature you did not want added is not a thing anyone means to do. Only No default signature here, and Discard on the old-draft card, switch them off.

Your default signature is added at the end of the message. With Dashes above your signature on, which it is until you change it, a short -- line sits above it; turn that off and the signature goes in on its own. If you picked a signature for the inbox you send from under Signature by inbox, that one is added instead of your default. It is added:

• when you start a new message,
• when you reply, in the thread or from the compose window, and
• when you forward a message.

A draft you reopen keeps the signature it was saved with, so resuming one never stacks a second copy underneath the first.

A reply to cold outreach sent from a cold inbox does not get your default. It carries the plain version of the signature you mapped to that cold inbox under Signature by inbox, or none when you mapped none. Sent from one of your own inboxes instead, it carries that inbox's signature. Any time you want a different signature than the one added, insert one by hand: type /signature in the message body, or use the + Insert button and its Signature row, where your default is marked (default).

Cold sequence emails work differently: your default is never added to them. Instead, each of your cold sending mailboxes can carry a signature you choose for it. Open Email settings, go to Composing, and use Signature by inbox, under Dashes above your signature. Cold emails get a plain version: your words and links, no images or layout, so a signature with a designed layout is not offered there. See Signatures on cold emails.

Signatures are yours alone. They are not shared with teammates. The same default applies whichever of your inboxes you send from, unless you choose a signature per inbox: Signature by inbox also lists each inbox you send ordinary mail from, set to Your default signature until you pick another. The signature follows the From: when you switch the From in a message, the signature in it switches to that inbox's signature, as long as you have not changed it. A signature you have edited in the message stays exactly as you left it. See Choosing who a message comes from.

A designed signature, one with columns, a photo or a logo, goes into a message as a single block that looks exactly the way the people you email will see it. Point at the block, or click it, and two links appear under it: Edit signature opens your signatures in settings in a new tab, and Edit inline lets you change the signature in this message only.

Edit inline turns the block into a table you can type in, with the same look, so you can change a title, a phone number or a line for this one message. Your saved signature does not change. Undo (Cmd+Z on a Mac, Ctrl+Z elsewhere) takes the message back to the single block, the same as any other change. The edited signature still counts as this message's signature, so a second one is never added below it.

Some designs use formatting that a table in a message cannot hold exactly, such as paragraphs with their own spacing inside a cell. For those, Edit inline is unavailable and the line This design uses formatting only Settings can edit. appears beside it. Change that design in settings instead, where the signature editor keeps it exactly.

Edit inline is on the compose window and the reply inside a thread, where signatures are added. A quoted original message never offers it: what someone else wrote stays exactly as they sent it.

The signature box shows your signature the way the people you email will see it. Click into it and paste a signature you already use, copied from another mail app, a signature generator or a message you sent, and it keeps its design: columns, spacing, colors, fonts, links and images stay where they were instead of being flattened into stacked lines. You can type into it and change it after pasting, the same as any other text.

A few things are repaired on the way in, so what you get is the signature as it was designed rather than what the copy carried with it. The gray block some browsers paint behind a copied selection is removed, colors and fonts written in older mail formats are kept, and images copied out of a web mail message load from their original address.

Above the signature box there is an Edit as HTML switch. You do not need it to paste a designed signature; it is there for markup you were handed as code, or for a detail the editor cannot reach. Turn it on and the signature box is replaced by a plain markup box, with a live preview under it that shows the signature the way it will be sent and updates a moment after you stop typing. Turn the switch off to go back to the editor, which picks up the markup as it now stands.

The switch is in both places a signature can be edited: the signature manager described above, and the signature panel in Email settings under Composing. It does not matter which one you opened.

A designed signature, one laid out in columns however you made it, is added to your messages as one block, shown exactly as the people you email will see it: its columns, spacing and images at their own size, with no frame around it. While you write you can move it or remove it in one go, and unless you use Edit inline on it, it goes out exactly as you saved it. Its saved wording is changed here: point at the signature, or click or tap it, and an Edit signature link appears under it that opens the signature manager in a new tab, so the message you are writing is never navigated away from. Edit inline, beside it, changes that one message only, as described above. A plain text signature behaves as it always has: it is added as ordinary lines you can edit in the message.

Most email apps do not show an image that is embedded inside a signature, which is how many signature tools and some mail apps copy one. So an image embedded in what you paste, and a file you upload, is stored at its own web address, and your signature points to it. There are two ways to add one:

• Paste or drag in a signature that has images. Each embedded image is uploaded for you and swapped for its web address. You see it the whole time.
• Click Upload image in the toolbar and choose a file. It is added where the cursor was.

Images can be PNG, JPEG or GIF files up to 1 MB each. A picture wider than 600 px is resized to 600 px wide, and details the camera saved inside the file, such as its location, are removed. An image with no size of its own is shown at up to 400 px wide, the width mail apps recommend for a signature. You can keep up to 50 signature images, and uploading the same image twice keeps one copy.

While an image uploads, a line under the signature box reads Uploading 1 image… and the save button reads Uploading images… until it is done. If an image cannot be added, a line says so: upload it again, or add it with Image from a web address. An image larger than 1 MB is left out, and the line says that too. Markup with an embedded image that you type in Edit as HTML is uploaded when you save; if an image cannot be added then, nothing is saved yet, the markup shows what was kept, and saving again saves it.