We are often asked to design and provide custom HTML email signatures to help our clients project their brand image well in all emails. However, it is important to note that the results can be unpredictable because of the generally poor, and hugely varied support for HTML across all email clients.


Email clients (such as Outlook, Gmail, Mail etc.), whether desktop or web based, do not have a consistent support for HTML. This means that email content styled with HTML can look completely different between who has sent it and who is reading it.

This is because email clients interpret HTML and then render out content that its own email viewer or editor understands. This commonly results in:

  • HTML tags being removed or inserted
  • Styling directives being removed
  • Styling directives being added.

Email clients can also alter you HTML email by trying to enhance the content, such as detect links. This can result in:

  • Adding default link styling to email addresses, web addresses and telephone numbers
  • Incorrectly adding link styling to general numbers, such as a Company Registration No.

Ad Blockers can also change your HTML email. We've seen situations where the emails signature's social media links are removed because the Ad Blocker software thinks they are ads!

It is also worth noting that when forwarding an email the HTML will usually be stripped away including formatting, particularly images. Email trails will also strip away more formatting - think of it as Chinese Whispers with each send and reply trying to re-interpret the HTML.


We recommend the email signature is kept simple with minimal styling and use of images. Consider stacking the information to help retain consistency for mobile screens.

Where possible, the signature is created in your email clients signature editor. Alternatively, we can provide you with an HTML file that you can open, copy the content and then paste into your signature editor.
Be aware that copying the HTML from different browsers (such as Chrome or Safari) can give different results such as font sizes.

Signatures in emails sent from your mobile should be kept even simpler and limited to text created in the mobile device's signature editor. We can provide HTML for this but much more of the styling is stripped out on mobile, particularly colours.

Useful information to provide to us at the start of the project includes:

  • Name and version of the email client used by all of your team

  • The font (including size and colour) of your default corporate email

  • Names, titles, contact details and link addresses for everyone requiring a signature

  • Who will be implementing the email signatures (eg. each employee or central IT support).

With a bit of thought and preparation you can have nice looking emails that will work in the best way possible with your chosen email client. Please feel free to get in touch if this raises any questions about your email signature.