Email signature
A signature that survives every mail client, carries the details business mail is required to carry, and stays quiet on a white message.
Email is not the web. Every value below is a literal, every layout is a table,
and nothing depends on a stylesheet the client is free to discard.
Two forms are supplied:
The signature
Full form — a white message is the design constraint
Jane Doe Principal Consultant Projectious GmbH Musterstraße 1, 10115 Berlin, Germany Projectious GmbH · Registered seat Berlin
Amtsgericht Charlottenburg, HRB 000000 · VAT ID DE000000000
Managing director: Jane Doe This message is intended only for the addressee and may contain confidential
information. If you received it in error, please tell the sender and delete it. |
Short form — replies and internal mail
Jane Doe Principal Consultant · Projectious GmbH |
Both specimens are rendered on white, because that is where a signature
actually lives. The surrounding page has a colour mode; a mail message
generally does not.
One rule, and it is vertical
A signature accumulates dividers as it accumulates fields — one under the name,
another above the legal block, another before the disclaimer — and each reads as
a section break in a message that is not sectioned. On a white background the
result is a small form stapled to the bottom of a letter.
So there are no horizontal rules at all. One vertical accent rule runs down
the left of the whole block: it marks the signature as a unit, ties it to the
brand, and costs one line instead of four. Everything else is separated by space
and by type size.
Do
Group the fields — identity, contact, address, legal — and separate the groups
with about 9px of space. Let the type sizes do the ranking.
Don't
Add a rule between groups, a coloured band behind the name, social icon rows, a
quotation, or a “please consider the environment” line.
Fields
Replace every [PLACEHOLDER]. Delete any row that does not apply — the block is
built so that removing a row leaves no gap behind it.
| Field | Required | Notes |
|---|
| Full name | Always | 15px, 700, midnight-9 |
| Job title | Always | Its own line — a title merged into the company line reads as part of the company |
| Company legal name | Always | The registered name, not the trading shorthand, wherever the legal block appears |
| Phone | Recommended | With country code; a signature is often read from another country |
| Email address | Always | Even though it is in the header — messages get forwarded |
| Website | Always | |
| Postal address | Regionally required | Street, postcode, city, country |
| Register details | Regionally required | Legal form, registered seat, register court and number, VAT ID, directors |
| Confidentiality notice | Optional | Two lines at most; delete it unless your organisation requires it |
What the law asks for
A starting point, not legal advice — confirm against your own jurisdiction
before shipping a signature.
| Jurisdiction | Business email must carry |
|---|
| Germany | Legal form, registered seat, register court and number, and every managing director (§ 35a GmbHG, § 37a HGB) |
| EU / UK | Company registration number, registered office address, and VAT number where registered |
| United States | No statutory signature requirement; confidentiality notices are convention rather than law |
| Canada | CASL requires sender identification and a postal address on commercial messages |
| Australia | ACN or ABN on business correspondence |
Construction
| Rule | Why |
|---|
Table layout, role="presentation" | Flexbox and grid do not survive Outlook’s Word renderer; the role stops screen readers announcing a data table |
| White declared on table, row, and cell | A client repainting for dark mode decides what to invert per element. White on the cell alone leaves the table around it unpainted — see below |
Each background written twice, as bgcolor and background-color | The background shorthand alone is not enough: several clients strip shorthands and keep longhands, and Outlook’s renderer prefers the attribute |
| Inline styles only | Most clients strip <style>, and none support custom properties — so no var(--pj-*) anywhere |
| Web-safe font stack | Brand faces will not load in a mail client; the stack degrades to a system sans without changing the layout |
| Maximum width 520px | Below the 600px that forces horizontal scrolling in narrow reading panes |
| Literal hex values | The brand steps, written out — see the table below |
| No images | A hosted logo is blocked by default in many clients and leaves a broken frame. The accent rule carries the brand with nothing to load |
| No background images | If a fill is ever needed, use the bgcolor attribute |
Declaring white three times is not belt-and-braces
It is the difference between a signature that survives dark mode and one that
does not, and it is the most common way this block breaks.
<table … bgcolor="#ffffff" style="…background:#ffffff;background-color:#ffffff;…">
<tr bgcolor="#ffffff" style="background-color:#ffffff">
<td bgcolor="#ffffff" style="background:#ffffff;background-color:#ffffff;…">
A client that repaints a message for dark mode works element by element: it
looks at each one, decides whether it has a background it should keep, and
inverts the rest. Declare white only on the <td> and the <table> around it
has no background to keep — so the cell stays white while its own container is
repainted dark. The result is a white island with a dark halo, or worse, the
dark text inverted to light and then drawn on the white cell that was kept.
Every enclosing element that has a painted area needs the declaration, and each
one needs it in both forms: the bgcolor attribute, which Outlook’s renderer
prefers, and background-color, because several clients strip the background
shorthand while keeping longhands.
Dark mode will recolour this, and that is fine
Several clients — Outlook mobile and some webmail among them — invert or shift
signature colours in dark mode, and none can be reliably prevented from doing
so. The signature is therefore built to survive recolouring rather than to fight
it: the hierarchy is carried by size and weight as much as by hue, so it still
reads when the palette is altered.
Colours
Three families, which is what a signature should have.
| Role | Value | Use |
|---|
| Heading | #1d3352 | The name |
| Primary text | #142438 | Title, phone |
| Secondary | #546a82 | Company, address |
| Link | #3a5a82 | Email, website |
| Legal and notice | #546a82 | Register details, confidentiality notice |
| Accent | #E05232 | The vertical rule, and nothing else |
Before shipping a change
- Send to Outlook (Windows), Gmail web, Apple Mail, and one mobile client.
- Reply to that message twice and check how the signature looks quoted inside a
thread.
- Turn on the client’s dark mode and confirm the hierarchy still reads.
- Forward it, to confirm nothing depends on the original message’s styles.