Set up the few lines that go at the bottom of every message you send — your name, role, and how to reach you. We’ll build a simple one first, then cover what a polished, professional signature should contain.
Set up a signature
Open Signatures
Click the Settings gear. In the left margin, under Set Up, click My email addresses, then open the Signatures tab.
Pick an address
Under Addresses without a signature, click the email address you want to set up.
Type your signature
Type it in the box. Use the toolbar to bold text, add a link, or change color.
Save
Click Save. Fastmail now adds it automatically to new messages from that address.
A signature is tied to an email address, not your whole account. If you send from more than one address, each gets its own — so you can have a formal work signature on one and a short personal one on another.
What to put in a signature
Keep it to four to six lines: your name, role, company, phone, and email or website. Plain text in a readable font travels best — it looks correct on phones, in dark mode, and in other people’s email apps.
Keep it simple to start. Skip inspirational quotes and large images, and avoid putting essential text inside an image (screen readers and blocked-image views can’t see it). You can always add a logo or color later.
Legal & compliance notices: check before you send. Regulated professions often require specific language — financial advisors may need SEC/FINRA disclosures; attorneys a confidentiality notice. The exact wording is set by your compliance team or governing body, not by us. This guide is general information, not legal advice.