Question: I'm building what will be a PDF in Sketch 3. 

I want to create a button (a rectangle box with "sign up" inside) that launches a mailto link when the person reading it clicks on it. 

I can't figure out how to 1) add links in Sketch, or 2) make the entire button (including the border of the rectangle box) clickable, vs just the text portion. 

Any help is appreciated!

Answer: 
After creating PDF without links, open it in Adobe Acrobat and choose the place where you want to link like in the image below:

[![enter image description here](https://i.stack.imgur.com/qZuY7.png)](https://i.stack.imgur.com/qZuY7.png)

Then choose Create Link in the menu and select the option "Open a Web Page":
[![enter image description here](https://i.stack.imgur.com/F6Edl.png)](https://i.stack.imgur.com/F6Edl.png)

Click Next and you will be prompted with a text box. Fill it with "mailto:person@address.com" without quotation marks. And you'll be done!

[![enter image description here](https://i.stack.imgur.com/9l6ED.png)](https://i.stack.imgur.com/9l6ED.png)

Hope it helps!
Found this on the Sketch Talk forum. Just confirmed that it works, even with mailto: links.

"Easiest way (which is how I did it in Illustrator too) is to paste the URL you want over the text you want to hyperlink, change the URL color to the same as the background, and send it to the back underneath the original text you wanted to link. Once you export, there will be an invisible hyperlink underneath the text!"