I have a mailto link on a page. It works as expected when the page is loaded by itself.
However when the page is loaded via a frameset in Chrome nothing happens. Wit
Possibly because your parent frameset is https, but Chrome now seems to treat the mailto link as insecure.
I just came across a similar issue when triggering a mailto link via
window.location = 'mailto:...'
Changing it to this worked around it.
window.open( 'mailto:...')