Resources Hub » Knowledge base » How Do You Add a Subject to a Mailto?

When designing an email campaign, marketers want to include plenty of ways for subscribers to contact them. And one popular method—for many years—was the mailto link. This link would then auto-populate an address into your preferred email client, making it easy to send an email.

With the simplicity of creating and including contact forms within email, is using a mailto link even relevant? What about adding a subject to a mailto?

What is a mailto link?

In short, a mailto link is a specific HTML link that, when clicked, will activate the user’s default email client and auto-populate the “To:” field. In an HTML email, the code used to create a mailto link looks like this:

<a href="mailto:[email protected]">Email is linked here.</a> 

Why you should avoid mailto

While mailto links were once considered a simple way to make responding to messages easier, these HTML links are now being blocked by more and more web clients due to safety concerns.

While mailto links were once considered a simple way to make responding to messages easier, these HTML links are now being blocked by more and more web clients due to “safety” concerns.


One of the primary safety concerns continues to be the fact that mailto links don’t tell you who exactly it is you’re sending your message to. Sure, hovering over the link’s anchor text or simply allowing your email client to load and populate your “To” field will show you the address—but that doesn’t tell you who the recipient is. Users have to do some sleuthing of their own to find out who this seemingly random address belongs to.

Half of the people using the internet will click on unknown links.

This information is startling because that means half the people using the internet and email are willingly opening themselves up to possible hackers that’d love for nothing more than you to click on the wrong link and end up losing valuable personal information.

While these concerns are very legitimate, there are still many marketing teams that prefer to use mailto links in their HTML emails. We’ll cover exactly how to do this, but to be clear, we think there are a variety of other ways to inspire responses to your marketing messages that are more successful and more secure than a mailto link. See more to this point here.

How to add subjects to a mailto

While more email and web clients are beginning to either block or discontinue the use of mailto links, there are still marketers that wish to include them in their email practices.

While the practice is widely considered poor email practice, those that use it often tend to ask how they can add a subject to a mailto link. Again, while this is regarded as poor email practice, there’s a code that allows users to add a designated subject to a mailto link:

<a href="mailto:[email protected]?subject=Subject line is here">Email is linked here.</a>  

How to measure the success of your mailto link

Measuring the success of your mailto link isn’t as simple as monitoring key performance indicators, which can be done when using contact forms. The best way to monitor the success rate of your mailto links is to use event tracking, if available with your analytics provider, or using something like Google Tag Manager to tag mail to link clicks.

Source: Trevor Ayers

Does using a mailto link really matter?

While many marketers are still using mailto links, the answer to whether they really matter anymore is a resounding no.

Again, this is because using mailto links are a security concern, especially in an age when computer hacking is all too common. This is why it’s flagged as a poor email practice, and why many email clients now block the function from actually working when the users attempt to click on mailto links.

What now?

Instead of focusing on how to use mailto links, why not turn your attention to using an HTML form instead? Learn how to create HTML forms for use in your emails today.

This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.

Get started with Campaign Monitor by Marigold today.

With our powerful yet easy-to-use tools, it's never been easier to make an impact with email marketing.

Try it for free