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:

FormSourceUse for
Fullbrand/email/signature.htmlFirst contact, and any message leaving the organisation — it carries the legally required details
Shortbrand/email/signature-short.htmlReplies and internal mail, where the full block repeated down a thread becomes noise

The signature

Full form — a white message is the design constraint
Jane Doe
Principal Consultant
Projectious GmbH
+49 30 000 000 00  ·  jane@projectious.work
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.

FieldRequiredNotes
Full nameAlways15px, 700, midnight-9
Job titleAlwaysIts own line — a title merged into the company line reads as part of the company
Company legal nameAlwaysThe registered name, not the trading shorthand, wherever the legal block appears
PhoneRecommendedWith country code; a signature is often read from another country
Email addressAlwaysEven though it is in the header — messages get forwarded
WebsiteAlways
Postal addressRegionally requiredStreet, postcode, city, country
Register detailsRegionally requiredLegal form, registered seat, register court and number, VAT ID, directors
Confidentiality noticeOptionalTwo 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.

JurisdictionBusiness email must carry
GermanyLegal form, registered seat, register court and number, and every managing director (§ 35a GmbHG, § 37a HGB)
EU / UKCompany registration number, registered office address, and VAT number where registered
United StatesNo statutory signature requirement; confidentiality notices are convention rather than law
CanadaCASL requires sender identification and a postal address on commercial messages
AustraliaACN or ABN on business correspondence

Construction

RuleWhy
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 cellA 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-colorThe background shorthand alone is not enough: several clients strip shorthands and keep longhands, and Outlook’s renderer prefers the attribute
Inline styles onlyMost clients strip <style>, and none support custom properties — so no var(--pj-*) anywhere
Web-safe font stackBrand faces will not load in a mail client; the stack degrades to a system sans without changing the layout
Maximum width 520pxBelow the 600px that forces horizontal scrolling in narrow reading panes
Literal hex valuesThe brand steps, written out — see the table below
No imagesA 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 imagesIf 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.

Colours

Three families, which is what a signature should have.

RoleValueUse
Heading #1d3352The name
Primary text #142438Title, phone
Secondary #546a82Company, address
Link #3a5a82Email, website
Legal and notice #546a82Register details, confidentiality notice
Accent #E05232The 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.