I'm having problem trying to add a link "mailto" to a part

Hi, I'm having problem trying to add a link "mailto" to a part of a text, using upfront theme (Spirit)
Let's say for example that I have to put a
For further informations please contact us at
email@adress.com
and I want to put a link "mailto" on the email address.
If I put link to a URL it doesn't accept mailto.
How can I do it ?