11 Email Signature Mistakes That Make You Look Unprofessional
Your signature is attached to every email you'll send this year. These eleven mistakes quietly undermine it — most take two minutes to fix.
The eleven mistakes
The broken image
Nothing says “didn't check” like a blue question-mark box where your logo should be. Fix: hosted https images, never dragged-in files — full diagnostic here.
The inspirational quote
“Be the change…” below your phone number costs you credibility with every recipient who's seen it mocked. Fix: delete. Your role is the message.
Image-only signatures
One big PNG of your whole signature: unreadable when images are blocked, uncopyable phone number, invisible to screen readers. Fix: real text + hosted images for the visual parts.
Six social icons
Nobody follows your Pinterest from an invoice email. Fix: LinkedIn plus at most one other active, professional profile.
Three phone numbers
Office, mobile, fax, Skype… recipients freeze. Fix: the one number you actually answer, as a tap-to-call link.
Or skip the manual setup
Autograph designs the signature on your Mac and installs it into Apple Mail in one click — images hosted at permanent URLs, assigned to the right account, and re-applied automatically when a macOS update or iCloud sync wipes it.
Download freeUnlock Pro — one-time, no subscriptionThe unsized logo
Renders fine on your Mac, arrives billboard-sized on phones. Fix: explicit width/height attributes — size guide.
Comic Sans energy
Decorative fonts either break (most clients don't have them) or work — which is worse. Fix: email-safe stacks: Helvetica, Arial, system fonts.
The novel-length disclaimer
Eight lines of legal boilerplate in bold black reads as paranoia. Fix: if required, style it 11px gray below the signature.
The stale promo banner
“Register for our March webinar!” in July. Fix: rotate banners monthly or remove them — a calendar reminder works.
Different signature on every device
Polished from the Mac, “Sent from my iPhone” from the phone — where you answer the urgent ones. Fix: same signature on both — how.
No signature at all
The other extreme: a bare sign-off makes every new contact google you. Fix: even a minimal name/title/company block beats nothing.
Zero of the eleven, by default
Autograph's templates are built so these mistakes can't happen — sized hosted images, safe fonts, quiet disclaimers, and the same signature on Mac and iPhone.
Download Autograph free See the templatesCommon questions
What's the single most damaging mistake?
Broken images — it's visible, it's on every email, and it signals carelessness. It's also the most fixable (hosted images).
How many of these does the average signature have?
Two or three. The most common combo: dragged-in logo (breaks), a quote, and no phone link.
What does a mistake-free signature look like?
4–7 lines, one accent color, real text, hosted images with explicit sizes, one CTA at most, tiny gray disclaimer if required. See the examples page.
The Apple Mail Signature Fix Kit
A free checklist: why Apple Mail signatures vanish after macOS updates, the iCloud sync gotcha that wipes them, and how to make your images render in Gmail and Outlook. Straight to your inbox.