One email signature standard for a whole company in Tanzania

Ten staff, ten signatures. One carries a logo image with the phone number set inside it, one omits the title, three give the mobile number in different formats, and on a phone with images blocked the logo-only signature shows nothing. The reader sees ten versions of one company.

This note sets out the case for one signature standard across every member of staff, what the standard includes and leaves out, and a field audit of a fictional ten-person company, using Google, Microsoft and W3C documentation.

Why does one signature standard matter?

A signature is the identity block on every message the company sends. Google lets an administrator create the same signature for everyone ¹. One standard gives the reader the same name, legal entity and contact lines from every sender, in English and Kiswahili, and gives the company one design to update when a number or an address changes.

What should the signature include and leave out?

Outlook signatures can hold text, links, pictures and a logo ³. The standard fixes nine fields and the rule that governs each.

The standard also leaves things out. A confidentiality line is included only where the sector needs one, in the Client's own wording.

• A long confidentiality block.
• A quotation or a slogan.
• Several competing links.
• Any detail set only inside an image.

Why must the signature survive blocked images?

Microsoft Outlook is configured by default to block automatic picture downloads, and the recipient sees an InfoBar with a Download Pictures option ². A signature whose phone number sits inside the logo shows nothing until the reader clicks. WCAG 2.2 requires non-text content to have a text alternative that serves the equivalent purpose ⁵, so the logo carries a text alternative and every contact line is text.

What contrast and size does the standard set?

WCAG 2.2 sets a contrast ratio of at least 4.5:1 for text, and 3:1 for large text of 18 point, or 14 point bold ⁶. WCAG is written for web content, and the desk applies its criteria to email. Gmail signatures can have up to 10,000 characters, and Google recommends footer images 70 to 100 pixels high by 300 to 400 wide, with a maximum of 100 high by 1000 wide ¹.

Does the signature affect deliverability?

Not directly. Google requires every sender to set up SPF or DKIM, requires bulk senders (more than 5,000 messages a day to Gmail accounts) to set up DMARC, and requires spam rates reported in Postmaster Tools below 0.3 percent ⁴. A signature does not replace authentication. A consistent signature makes an authenticated message recognisable once it arrives.

What the NEMBO desk prepares

The Client shares each person's name, title, phone and email, the website, address and logo, the one action the signature should invite, and any services or credentials to show. Zatra Consultants Limited checks the content, and NEMBO returns one design for the whole team, English and Kiswahili each written, built for desktop and phone with live call and mail links, and each new signature produced from the same design ⁷. The set is delivered in hours and quoted in writing.

The desk prepares the signatures. A confidentiality or disclaimer line is the Client's wording, confirmed by the Client's adviser where the sector requires it. The desk does not administer the Client's mail platform or guarantee delivery.