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How to setup your HTML email signature in Mozilla Thunderbird for macOS

Install your HTML email signature in Thunderbird on MacOS no time! This article includes a link to our free Thunderbird on MacOS email signature installer app, our easy step by step HTML email signature install guide, screenshots, videos and troubleshooting FAQ.

It's never been easier to create a new email signature for Mozilla Thunderbird for Mac. Check out our beautiful email signature templates and easy to manage email signature software, that makes creating email signatures for Mozilla Thunderbird for Mac a breeze.

Before you start

Before you start

Great news! We've officially released our new signature installer app for macOS. Simply download, install, and follow the guide to setup your signature in just minutes with our all-new automatic update functionality!

Try our Signature Installer App for Thunderbird

We've spent the past few months developing a brand new signature installer app for macOS which works with all of the major email clients including Thunderbird for Mac. By using the signature installer app, you will be able to easily install your email signature in the following email clients:

  • Apple Mail (OS Sierra and newer)
  • Outlook for Mac 2016
  • Outlook for Mac 2011
  • Postbox
  • Thunderbird for Mac

Installing your email signature with our app takes just seconds. You simply select your email client and email account, then enter your unique signature key or insert your custom HTML code and the installer app will install your email signature into your desired email client for you.

Not only does the signature installer app install your email signature for you, it will also automatically update your email signature whenever any changes are made to your email signature from your account. This is only applicable if using your signature key.

Download the Installer App for mac


Next Step

Click on our Install: Signature Installer App below to follow our written installation guide with screenshots.

If for whatever reason you don't want to use our Signature Installer App, you can still install your email signature manually by following our Install: Step-by-Step guide instead.

If you run into any issues during your HTML email signature installation in Thunderbird for Mac, please see the Troubleshooting FAQ before contacting support through your member account.

Install: Signature Installer App

Install: Signature Installer App

Before following the below instructions, you must have the ESR Signature Installer App installed. If you do not yet have it installed, you can download it from the Before you start section above.

Installing your email signature in the signature installer app

1
Step One

Open the ESR Signature Installer app and click the Add New Email Signature button.


2
Step Two

Select your Mozilla Thunderbird email client.


3
Step Three

Select the email account you want your email signature to be installed for.


4
Step Four

Paste your email signature key and click Save Key. If you have HTML code instead of a key, click Advanced Settings, paste in your HTML code and click Save.


5
Step Five

Once you click Save Key, your email signature will be installed within Mozilla Thunderbird for Mac. Simply compose a new email and your signature will automatically be inserted!

compose new email in thunderbird


It's as easy as that!

Install: Manual Step-by-Step Guide

Install: Manual Step-by-Step Guide

1
Step One

Open Mozilla Thunderbird for Mac.


2
Step Two

From the top menu, select Tools then Account Settings.

select tools then account settings

3
Step Three

From the Account Settings window you will see a list on the left side with your mail accounts and some settings, select your email account.

Under your Default Identity section you will see your signature setting. Tick the Attach a signature from a file instead (text, HTML, or image): checkbox then click the Choose... button.

tick the attach signature checkbox

4
Step Four

Now we want to navigate to our email signature file and select it. If you have had your email signature sent to you, access it from your email, save it to a location on your computer, then select it from your Thunderbird account settings.

navigate to and select email signature

5
Step Five

Press OK to save your account settings, then compose a new email.

Your email signature will automatically be inserted into your emails when composing a new email.

NOTE: Your email signature will show the table and cells when composing a new email. These won't show once the email has been sent.

compose a new email within Thunderbird

All Finished!

That's it. Try your email signature now by composing an email to yourself or a friend!

Troubleshooting: FAQ

Troubleshooting: FAQ

If you're experiencing any issues installing your email signature within Postbox for Mac, you'll likely be able to find a resolution here.


I'm experiencing issues with the ESR Signature Installer App

Although we've thoroughly tested it, the ESR Signature Installer App is still in BETA so it's possible that you may experience some issues. If you do come across any issues when using the app, please get in touch with our friendly support team.


My email signature doesn't look right when I compose an email

When composing an email within Mozilla Thunderbird for Mac you will see the table and cells of your email signature outlined, this is completely normal. When you send your email, it will display correctly to your recipient.


I am composing an email and I can't click on any links or social media icons

In compose mode, most email programs won't allow you to use the links in your email signature. Check to see if your email signature has been installed correctly by sending a test email to yourself instead. The links and social media icons should work when you receive the email.


Still experiencing issues?

If you're a member of Email Signature Rescue, you can submit a ticket to our friendly support team through your member account using the red help button. If you're not a member and need help creating or installing your HTML email signature, consider joining Email Signature Rescue for assistance.

Troubleshooting: Where do I find my email signature key?

Troubleshooting: Where do I find my email signature key?

  • If you are an Email Signature Rescue member and are logged into your account, you can find your key on your dashboard.
  • If you have been emailed your signature key, go to the email and you'll find your 12 character key there.
  • If your email signature is managed by an account administrator or reseller, please get in touch with them and have them supply you with your signature key.

Troubleshooting: Where do I find my email signature HTML file?

Troubleshooting: Where do I find my email signature HTML file?

  • If you are an Email Signature Rescue member and are logged into your account, you can download your HTML file from your dashboard or view it by selecting Full Screen Preview.
  • If you have been emailed your signature file, open the email and you'll find it attached.
  • If your email signature is managed by an account administrator or reseller, please get in touch with them and have them supply you with your signature file.

Troubleshooting: I don't have an email signature key or HTML file

Troubleshooting: I don't have an email signature key or HTML file

If you don't have an email signature key or HTML file, consider joining Email Signature Rescue now and get creating! We offer over 30 professionally designed and tested email signature templates, tools and features to create and manage your email signatures online and a whole lot more.

Join Email Signature Rescue now

Over 90,000 email signatures created with Email Signature Rescue
  • cent21
  • dude-perfect
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No Design Skills

No design skills required. Your signatures will look as beautiful as our examples. 20 easy to customize templates included.

No Tech Knowledge

Whether you’re a solo business owner, hairdresser, real estate agent or dog walker, anyone can create and install a signature!

Works With

Install in nearly all major email clients including Gmail, Apple Mail, Outlook, iOS and more. 50+ email clients, apps and software supported.

Reliable & Tested

We refine our HTML code and conduct extensive testing regularly to ensure it is industry-leading and works across all major email clients.

Save Time

Create, customize, edit, manage and deploy HTML email signatures from one central, easy to use system.

Save Money

No expensive IT staff, developers or designers needed. From signature design, to installation and support, we take care of it all.

Easy Duplication

10, 20, 30 or 100 staff? No worries! Duplicate signatures you’ve already created from the Dashboard to create multiple signatures quickly.

Support if you need it

Hit a snag? Help is only an email away. We're here for help with any design, installation and technical issues, should you need us.

Everything you need to create, customize, manage and deploy HTML email signatures.

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