Using mailto: for sharing a page vs a form

It seems the only questions regarding UX and <a href="mailto:email@example.com"> vs forms are about contact forms, but I'm interested in figuring out what the best way to help the user share a page would be.

First issue is the fact that nothing is going to happen if no mail client is configured when clicking a mailto: link. Someone made a way to detect this, so let's assume that works, and we're going to have a form for sharing a page for those users where mailto: fails.

Question is, should I

• always resort to a form?
• prefer mailto:, unless no e-mail client is configured? The e-mail will of course be prefilled with a subject and a link to the page being shared.

My theory is that it would seem more personal to receive an e-mail sent directly from a friend instead of our company email, sparking more interest. The mail client might also auto complete the friends e-mail address.

The fields for the form would be something like:

• Your email
• Your name
• Friends email
• Subject (prefilled with something like "Shared from example.com: [Page Title]")
• Optional text

Fields will be prefilled if we know the user already. I'm also open to suggestions here.

Obvious con when using mailto: is the inability to track if the mail is opened (if the recipient clicks the link, that can of course be tracked), due to not being able to use html. Tracking if the e-mail is actually sent would also be impossible.

Always showing a form would allow us to save user name and e-mail, track if the e-mail is sent and track if it's viewed by the recipient. So there are great benefits for us, if we always show the form, but if it prevents people from sharing the page, it doesn't make much sense.

In the end it's all about getting people to share the page. What's the best way to share a page by e-mail?