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Email signature format: How to structure a clear and effective email signature
TL;DR
The correct email signature format puts the sender's name and job title first, with the company name and contact details in a compact block underneath and optional elements below.
Exclaimer's design guidelines recommend tables for the layout and a width of 320 to 600 pixels, with 450 pixels recommended. A banner should be at most 600 pixels wide.
When an email is converted to plain text, Exclaimer's plain text article says the HTML formatting is removed along with images, and horizontally aligned elements appear underneath each other.
In Exclaimer's State of Business Email 2025 research, 92% of IT leaders agreed that consistent, well-managed email signatures build trust, yet 80% still rely on manual methods or user self-service.
What is an email signature format?
An email signature format is the structure that organizes contact details and branding at the end of a business email, including the order and layout of the information.
In Exclaimer’s 2026 survey of 2,000 UK and US adults, people cited these as trust signals in a business email:
Full contact details: 45%
A professional email address on a company domain: 44%
A clear sender name: 31%
A company logo or branding: 24%
A professional and branded email signature: 23%
The examples page breaks the same figures down by age group.
What is the correct email signature format?
The correct email signature format puts the sender's name and job title first, with the company name and contact details in a compact block underneath. Optional elements, such as a logo or a banner, go below that.
Exclaimer's design guidelines recommend building the layout with tables. Tables and table cells can be nested for more complex grids, though it's best to avoid excessive overlays with user photos and background shapes. An email signature should be 320 to 600 pixels wide, with 450 pixels recommended, and a banner at most 600 pixels wide. An email signature wider than 600 pixels can cause display issues on smaller screens.
Images should be uploaded at the size they will display, in JPG, JPEG, PNG, or GIF format. Consider how dark mode may affect color choices.
Core elements (always include) | Optional or conditional |
|---|---|
Full name | Social media icons |
Job title | Company logo (recommended) |
Company name | Email banner |
Phone number (external emails; include the country code) | Photo |
Email address | Feedback survey |
Website URL | Custom links, such as appointment booking |
| Award or certification images | |
Company postal address | |
Email disclaimer, where required |
A simple layout in plain text:
Jane Smith Marketing Manager | Example Company +1 (555) 123-4567 | [email protected] | example.com
Email signature format examples
Corporate email signature with contact details and banner
This layout pairs contact information with a promotional banner. It includes:
Name and job title at the top
Direct contact details
Social icons for additional communication channels
A banner for company achievements or news
A legal disclaimer at the bottom
Healthcare email signature with promotional banner
In healthcare settings, an email signature can carry promotional messaging alongside essential contact details. This layout includes:
Sender name and role
Direct contact details
Organization branding
A banner encouraging new patient registrations
A longer legal disclaimer
Brand-focused email signature format
An email signature can be designed around brand visibility. In this format:
The company logo is a prominent visual element
Sender information sits alongside the logo
Action links let recipients book calls or access services
A disclaimer appears below the contact information
Email signature with feedback request
This example includes:
A professional headshot
Contact details and company information
A one-click feedback survey embedded in the email signature
How wide should an email signature be, and how big should the images be?
Exclaimer's design guidelines say an email signature should be 320 to 600 pixels wide, with 450 pixels recommended, and a banner at most 600 pixels wide.
Exclaimer's image file requirements allow uploaded images up to 300KB and 2048 by 2048 pixels, with a minimum of 4 by 4 pixels. Upload each image at the size it will display, not resized in the designer. Images can be embedded, which means uploaded directly from your device into the email signature template, or linked, which means hosted on a public-facing server and referenced by a hosted URL. PNG, JPG, and JPEG are recommended; GIFs can also be used, and SVGs aren't supported within Exclaimer.
Tip
For dark mode, Exclaimer's dark mode support article recommends images with a light background so dark text can still be seen, and a light-colored border around text-based logos or tagline images before you upload them.
For dimensions, file size, and banners in more detail, see our email signature size guide.
How does classic Outlook render an email signature?
According to Microsoft's documentation, classic Outlook uses a Word-based HTML processing engine that has limited support for standard CSS margins and padding on HTML elements. Classic Outlook also doesn't natively support CSS background images on sections and columns, and it uses VML (Vector Markup Language) elements to render background images.
Exclaimer's design guidelines say to use tables to structure the layout.
"Tables are your friend. They let you create a more structured design, almost like a piece of architecture — you build the frame first, then put the content inside it. When you're starting a design, think about how many rows and columns you'll actually need before you start filling anything in. And don't be afraid to nest tables within tables. That's what ensures things behave correctly across most devices, especially when it comes to alignment."
What happens to an email signature in plain text?
Exclaimer's plain text article says that when an email is converted to plain text, the HTML formatting is removed along with images, and horizontally aligned elements appear underneath each other. Outlook displays a warning message about what will be lost in plain text mode, and shows the full hyperlink when plain text is used.
Which fonts should I use in an email signature?
Font | Windows | iOS | iOS13 | Android |
|---|---|---|---|---|
Arial | Available | Available | Available | Available |
Courier New | Available | Available | Available | Available |
Georgia | Available | Available | Available | Available |
Times New Roman | Available | Available | Available | Available |
Calibri | Available | Not available | Not available | Not available |
Source: Exclaimer's web safe fonts support article.
Some fonts, especially custom fonts, aren't available on every device or operating system, so consider a font stack of fallback fonts. End the font stack with a generic font family name, because generic families can be shown on all devices. If you use classic Outlook, Exclaimer recommends font stacks for server-side email signatures only, and says new Outlook isn't affected.
For text size, Exclaimer's design guidelines suggest 11 to 12 points for the name and job title and 8 to 10 points for contact details. Disclaimers and legal text can go down to 7 to 8 points.
For more, see our email signature fonts guide.
How do I make an email signature work on mobile?
Exclaimer's design guidelines say to keep designs compact and simple to avoid horizontal scrolling, and to test email signatures on mobile devices where possible.
A fixed width can be set on both tables and whole templates to avoid an email signature resizing on smaller device screens. Keep the width between 320 and 600 pixels, with 450 pixels recommended.
How do I keep an email signature simple and well structured?
Keep the email signature to essential information, and use tables to structure the layout. Exclaimer's design guidelines say tables and table cells can be nested to create more complex grids, though they suggest avoiding excessive overlays with user photos and background shapes. Avoid overloading the layout with graphics and banners.
Do email signature images need alt text?
Yes, add descriptive alt text to every image that carries meaning, such as the logo or a headshot, and describe what the image is, for example, “Example Company logo”.
For purely decorative images, leave the alt text empty (alt="") rather than missing.
What mistakes should I avoid when formatting an email signature?
Common mistakes include:
Including more than essential contact details
Using an email signature wider than 600 pixels, which can cause display issues on smaller screens
Not uploading images at the size they will display
Adding social icons for profiles that don’t matter to the role
Placing banners and other promotional content above the sender’s name and contact details
In Exclaimer’s State of Business Email 2025 research, 33% say employees ignore email signature guidelines.
How do I keep email signature formats consistent across an organization?
Define a standard email signature format: the order of contact details, the branding elements, and any required disclaimers.
Give employees approved pre-designed templates, so each person starts from the correct format.
Update contact details when roles and contact information change.
Apply updates centrally when branding, campaigns, or legal requirements change, so each employee doesn’t have to make the change.
To see how your formatting will render, try our free email signature generator.
How does Exclaimer keep email signature formats consistent?
With Exclaimer, setup and updates are done entirely from a web portal, with no PowerShell scripts, GPOs, or custom code.
The drag-and-drop designer builds and updates email signature templates without HTML or coding skills.
Brand Kits store approved logos, fonts, colors, banners, meeting backgrounds, and disclaimers, and updates apply automatically everywhere a kit is linked.
Disclaimers are applied server-side by rule, per user, region, brand, or audience, and employees cannot edit or remove them. Exclaimer’s disclaimers support legally compliant emails and don't constitute legal advice or guarantee compliance.
Role-based access control lets IT retain governance while delegating design and content rights to Marketing, HR, Legal, or Compliance, each with defined permissions.
See Exclaimer’s email signature management solution, or book a demo.
