Yahoo Mail's signature setup isn't complicated, but it is well hidden — the option sits two menus deep, off by default, and easy to give up looking for if you don't know its name. Once you find "Writing email" in settings, the rest takes under a minute. This guide gets you there directly, plus the per-address detail that catches anyone with more than one Yahoo address.
Where Yahoo hides the signature setting
Yahoo's signature setting lives under Settings → More settings → Writing email — not somewhere more obvious like an account or profile tab. If you've gone looking for it before and given up, that's why.
The other detail worth knowing upfront: signatures in Yahoo Mail are off by default. Even after you write one, it won't attach to outgoing mail until you switch on the toggle for that specific address.
Build it first
Finish your signature in Signoff Craft before opening Yahoo — name, role, company, the link or two you actually want, a logo if you have one. Check the preview; that's exactly what gets copied.
Wait for a logo to finish loading before you copy. An unfinished upload copies as a broken image reference, which shows up blank once it's pasted into Yahoo.
Click Copy signature in the builder. Yahoo's signature editor is a formatted (rich) box, the same kind as Gmail's — this is the version you want, not the raw HTML source.
Step-by-step: adding your signature
Open Yahoo Mail in a browser and sign in.
Click the Settings gear icon in the top-right corner.
Click More settings at the bottom of the panel that opens.
In the left-hand menu, click Writing email.
Find your email address and switch on the toggle next to it — this is the step people miss, since the text box underneath is visible whether the toggle is on or off.
Click into the signature box and paste with Cmd+V (Mac) or Ctrl+V (Windows). Your formatting, links, and logo should appear as they did in the Signoff Craft preview.
The setting saves as you go in the current Yahoo Mail interface — there's no separate Save button to hunt for. If you land on an older version of Yahoo Mail with a visible Save button at the bottom of the panel, click it too, just to be sure.
If you have more than one Yahoo address
Yahoo lets you set a separate signature for each address on the account. The toggle and text box under Writing email are per-address, so if you use two Yahoo addresses for different things, you'll do this setup twice — once per address.
A note on the Yahoo Mail app
The Yahoo Mail mobile app has its own signature setting, reached through the profile icon in the app, then Settings, then your account, then Signature. ⚠️ Whether the mobile app's field carries the same rich formatting as the web version can vary by app version — worth pasting your actual signature there and checking it before you rely on it, rather than assuming it behaves exactly like the web setup.
If something looks off
- Signature isn't showing up on sent mail at all: the toggle next to your address in Writing email is probably still off — the most common miss.
- Logo missing or broken: it wasn't finished uploading in Signoff Craft before you copied. Go back, let it fully load in the preview, then copy again.
- Formatting collapsed or spacing looks off: you likely pasted through another app first. Re-copy straight from Signoff Craft into the Yahoo box, no detour through a doc or notes app.
- ⚠️ Signature seems to cut off partway through: some webmail signature fields cap how much formatted content they'll keep. If yours is unusually heavy (a large CTA button, a big logo, several links), that's worth testing directly in Yahoo rather than assuming everything will survive — this hasn't been independently confirmed for Yahoo specifically, so treat it as a thing to check, not a rule.
One toggle, one paste
The whole thing is genuinely two steps once you know where they are: switch on the toggle for your address, paste the signature. If you haven't built yours yet, do that first in Signoff Craft — the Yahoo side takes less time than reading this guide did.
Create your signature
Put this into practice — pick a template, add your details and copy a polished signature into your inbox in minutes.