This is definitely something that you can do! You’ll want to create a new custom email theme and then when you're in your email theme’s template, scroll down to the bottom where your footer starts, it should be around line 62. Then just simply replace this code: 

<br>This email was sent to <a style="color:#1488b9;" href=“{{ recipient.email }}”>{{ recipient.email }}</a>. To stop receiving emails, <a style="color:#1488b9;" href=“{{ settings.site.unsubscribe_url }}”>click here</a>.

It's usually just on one line(62), but I've spread it out below so that you can clearly see the code.

With this code below, just remember to change out kevincoleman.rocks for whatever your custom domain is! This will direct a recipient to the page where they can edit all of their account information. 

<br>This email was sent to <a style="color:#1488b9;" href=“{{ recipient.email }}”>{{ recipient.email }}</a>, you can update your email address <a style="color:#1488b9;" href=“http://www.kevincoleman.rocks/forms/signups/{{ recipient.id }}/edit”>here</a>. To stop receiving emails, <a style="color:#1488b9;" href=“{{ settings.site.unsubscribe_url }}”>click here</a>.  

Same as above, the image below is spread out so that you can see all of the code, but when you insert the code, you'll want to keep the spacing the same as the code above so your email's spacing is ok.

It'll look something like the email below depending on what email theme you're using. 

Let me know if you have any trouble with that!