May 29, 20263 min readinstall-guides, apple-mail

How to add an email signature in Apple Mail (Mac, iPhone, and iPad)

Step-by-step instructions for adding an HTML email signature in Apple Mail on macOS and iOS, plus fixes for the formatting and image problems that trip everyone up.

The MailSigCraft Team

MailSigCraft

macOS (Apple Mail on your Mac)

Open Mail, then from the menu bar choose Mail → Settings (older versions: Preferences).

Go to the Signatures tab.

In the left column, pick the email account you want the signature for. If you create it under All Signatures, it won't be assignable to a specific account.

Click the + button to create a new signature and give it a name.

Uncheck "Always match my default message font" — leaving it on strips your fonts and colors.

Select everything in the signature preview box and delete the placeholder text.

Paste your MailSigCraft signature in. Use Edit → Paste (Cmd+V) — the images and layout carry over.

At the bottom, set Choose Signature to your new signature so it's applied to new mail automatically.

If the paste looks plain, see "Images and formatting disappear on paste" below — it's almost always the font checkbox or a clipboard issue.

iPhone and iPad (Apple Mail on iOS / iPadOS)

iOS Mail signatures are managed in Settings, not inside the Mail app:

Open Settings → Apps → Mail (older iOS: Settings → Mail).

Scroll to Signature.

Choose Per Account if you want different signatures for different mailboxes, then type or paste.

To keep rich formatting, copy your signature from an email you sent yourself, long-press in the signature box, and choose Paste and Match Style off — i.e. plain Paste.

iOS strips most rich formatting from typed signatures, so the reliable trick is: email the finished signature to yourself, open it in Mail, copy it, then paste it into the Signature field. Formatting survives the round-trip far better than typing it.

Common problems

Images and formatting disappear on paste (macOS). This is the "Always match my default message font" checkbox. Uncheck it, then re-paste. If it still strips, quit Mail completely (Cmd+Q), reopen, and paste again — Mail caches the signature editor state and a relaunch clears it.

The signature shows as a code block or raw HTML. You pasted the HTML source instead of the rendered signature. In MailSigCraft, use Copy to clipboard (not "Copy HTML") so the rich version lands on the clipboard, then paste.

Images vanish after you quit Mail. Older macOS Mail versions only keep pasted images if the signature file is saved correctly. Make sure you clicked away from the signature (so it commits) before quitting. If images keep dropping, host them on a CDN with absolute URLs instead of embedding — MailSigCraft does this for you.

Signature is too big on Retina screens. Apple Mail renders at the image's native pixel size. Export logos at 2× the display size and set explicit width/height so they scale down crisply instead of looking oversized.

Dark mode washes out your colors. Apple Mail on macOS respects dark mode in the composer. Avoid pure-black text on transparent backgrounds; use a slightly off-black and test in both appearances.

Build it once in MailSigCraft, copy it to your clipboard, and paste it into each device. The same signature will render correctly across Mac, iPhone, and iPad — and in your recipients' inboxes too.