Just after posting the question I tried to remove the quotes from the href in the theme options and it worked.
<a href=mailto:[email protected]>[email protected]</a>
Another solution I considered was to use .htaccess redirects in a way such it redirects to whaterver the theme decided to point to a mailto:
Redirect 301 /[path-to-wherever-metallex-points-to] mailto:[email protected]
-solution 2 source-
So if you find yourself in a similar situation, you have the choice between two solutions.