[Plugin: Contact Form 7] Two emails being sent

When my form callback function (on_sent_ok) contains an ajax call via jQuery’s $.post() , I get two emails sent from via the form submission. This is the email sent via the Contact Form 7 plugin. These are two identical emails, sent at the same time, not one email with the same address twice.

The odd thing is, in Chrome’s network monitor, the form’s ajax post request (to itself, the current URL) is only being called one time, yet internally in that call, contact form seven is generating two emails. It’s not like my function is re-submitting the form in any way. When $.post() is not present in my function, I get one email.

Why would my callback, which runs after Contact Form 7 submission success, have any affect on the original form post?

https://www.ads-software.com/extend/plugins/contact-form-7/