A good cold email signature is short and plain text: your name, your business, a phone number, one link at most, and a mailing address for legal reasons. Skip images, logos, banners, social icons and a block of legal text. The signature has one job, which is to let a stranger confirm you're a real person who can be reached.
People spend an afternoon designing a signature with a logo and four social icons, then wonder why their cold emails land in spam. This guide covers what belongs, what doesn't and why, with three examples at the end.
What a signature is for
In a cold email, the signature answers a quiet question the reader asks after the first lines: who is this, and can I check? A phone number and a business name let them look you up. A real name shows there is a person behind the message. That's all it needs to do.
It is not an advertisement. The body of the email makes the case. A signature loaded with offers, award badges and taglines makes the email look like marketing mail, which is the opposite of what you want. The general approach to sounding like a person is in how to write a cold email that gets replies.
Name, business, phone
Three lines are the core. Your full name. Your business name, and your role if it helps ("Owner" is fine, and it also tells a small-business reader they're hearing from the decision maker). And a phone number that you will answer.
The phone number does more than people expect. It makes you checkable, it gives the reader a way to reply by calling, and many owners prefer that. If you don't want to publish a mobile, use a business line. A number that goes to voicemail is better than none.
One link, not five
If you include a link, make it one: your website. Each additional link is another thing for a spam filter to evaluate and another distraction for the reader. A signature with a website, LinkedIn, Facebook, Instagram, a calendar link and a podcast looks like a newsletter footer.
Some senders skip the link entirely in the first message, and that's reasonable. The reader can find you from your business name. If you do include one, use a plain address like brightpath.example, not a tracked or shortened link. Shortened links hide where they lead, which is the sort of thing spam filters watch for.
The mailing address, and the opt-out line
In the US, the CAN-SPAM Act requires commercial email to include a valid physical postal address for the sender, plus a clear and conspicuous way to opt out. The address can be a street address, a PO box registered with the post office, or a private mailbox registered with a commercial mail receiving agency. A single line in the signature does it.
Add one sentence for the opt-out: "If you'd rather not hear from me, reply 'no thanks' and I'll remove you." Honor it quickly (the law gives you up to 10 business days, but do it the same day). Rules in other countries differ and may be stricter, and some professions, including financial advice, insurance and law, have their own solicitation rules, so check with the relevant authority. The broader basics are in how to send cold email that is not spam.
This is the one part of a plain signature that is there for the law, not for the reader. Keep it small and in the same plain type as the rest.
No images or logos
A logo in a signature feels harmless. In a cold email it causes several small problems. Images have to be loaded from somewhere, and many mail apps block them by default, so the reader sees an empty box or a red X. Some clients show the image as an attachment, which makes a plain note look like it has files on it. An email that is mostly image with little text can look suspicious to filters. And an image hosted on a remote server works, in effect, like a tracking pixel, which many people don't want.
I can't tell you exactly how any one filter weighs these, and nobody outside the provider can. The safe course is to leave images out of the first message and let the words do the work. If your brand really needs a logo, add it to later messages once someone has replied and you're in a conversation. The mechanics of filtering are in why cold email lands in spam, mechanically.
Plain text versus HTML
Plain text means no fonts, colors or buttons, just characters. In Gmail you can switch a message to plain text mode from the three-dot menu in the compose window. Plain text signatures are quick to read on phones, can't break across different mail apps, and look like they came from a person.
If you use a standard Gmail signature in the settings, keep it to plain lines of text with no images, no fancy fonts, and no tables. Test it: send yourself a message and open it on a phone and on a desktop. If it looks the same, you're fine. If you also read the Gmail basics in how to send cold emails from Gmail, you'll see this fits with the rest of a plain setup.
A sign-off that sounds like you
The words before your name matter slightly. "Best regards" and "Sincerely" sound like a form letter. "Thanks," "Talk soon," or just your first name sound like a person. Pick one and use it consistently. Avoid "Looking forward to hearing from you" in a first cold email, since you haven't earned the expectation. If the email ends with a question, you can put your name right after it.
Don't add a disclaimer block ("This email is confidential...") to a cold email. It's meant for internal mail and legal exchanges, and on a message to a stranger it looks absurd and adds length. Take it off your default signature if it's there.
Three example signatures
A sole proprietor selling to local shops:
Sana Reddy
Owner, Fieldwatch Security
(555) 010-0191
fieldwatch.example
214 Fulton St, Suite 4, Springfield, ST 00000If you'd rather not hear from me, reply "no thanks" and I'll remove you.
A small agency with a team, sending from a business domain:
Imani Cole
Orchard Web Studio
(555) 010-0176
PO Box 118, Riverton, ST 00000Not relevant? Just reply "stop" and I won't write again.
A founder with no website yet:
Jorge Vega
Founder, Routewise
(555) 010-0119
88 Mill Lane, Unit 2, Hartwell, ST 00000If this isn't for you, tell me and I'll take you off my list.
Each one is five or six lines, plain text, with a real address and a way to opt out. Nothing else.
Rocketship sends from your own Gmail, so the signature you set up there is the one that goes out. For how it runs, see the AI workers page, and for using it inside Claude, the Rocketship connector.
A plain signature takes five minutes and removes a handful of small ways to look like spam. Rocketship finds the buyers, emails them from your own Gmail, follows up, and books the meeting on its own. Plans that get you customers start at $24.99 a month (Launch), and every monthly plan starts with a 7-day free trial, card required.