How to Add an Email Signature on iPhone (With a Photo That Actually Works)
iPhone Mail supports rich signatures with images — but the obvious way to add one silently breaks the images for everyone you email. Here's the full setup, and the method that actually survives.
First, the honest facts: signatures you create in Apple Mail on a Mac do not sync to your iPhone (iCloud only syncs them between Macs), and iOS keeps one signature per account, set on the device itself. So the iPhone needs its own setup — here's how.
Step by step
Find the signature setting
On iOS 18 and later: Settings → Apps → Mail → Signature (under Composing). On iOS 17 and earlier, Mail sits directly in the Settings list.
Choose All Accounts or Per Account
Per Account lets each address have its own signature — useful if you mix work and personal.
For a simple text signature, just type it
Name, title, phone — done. For a designed signature with a photo or logo, keep reading.
Don't paste images from an email
If you copy a signature out of a received email and paste it here, iOS rewrites images into internal webkit-fake-url:// references that resolve nowhere — recipients see broken images. This is the classic trap.
Copy clean HTML instead
The images must be hosted web images (https URLs), and the copy must carry the HTML — not the rendered image data. Autograph does this for you: click Set up iPhone on your Mac, scan the QR code, and tap Copy signature on the page that opens.
Paste into the Signature field
Delete what's there, then tap-and-hold → Paste.
Fix the styling if needed
If fonts or colors look off after pasting, shake your iPhone and tap “Undo Change Attributes” — it restores the formatting iOS mangles on paste.
Don't panic at the preview
Images may show as broken squares in the signature box and compose window, and in Dark Mode the text can look invisible. Both are normal on iPhone — recipients see the real signature, with images and correct colors. Send yourself a test to confirm.
The one-minute version
Design the signature in Autograph on your Mac, click Set up iPhone, scan the QR code, tap Copy, paste. Done — with images that survive.
Download Autograph free See the templatesCommon questions
Why do images in my iPhone signature show as question marks or broken squares?
Either the image reference is a dead internal one (pasted image data — recreate the signature from clean HTML with hosted images), or it's a live web image that iPhone simply doesn't load in the signature preview. If a test email shows the image to recipients, the signature is fine.
Does my Mac's Apple Mail signature sync to my iPhone?
No. iCloud syncs signatures between Macs only. The iPhone signature is set on the device — Autograph bridges the gap with a QR code flow.
Why does my signature look black-on-black in Dark Mode?
The iOS composer paints its dark background behind your signature's dark text but doesn't adapt the colors. Recipients' mail apps render it correctly — verified by sending a test to Gmail.