Why does the message "Oops.. Reached your limits" appear when I try to send my form via email?

Further, when I tried emailing the link using the "Share Form" -> Email function under "Publish", entered the email to send to and captcha information, I get an "Oops.. Reached your limits" pop-up upon hitting send. 

You got this message because of the limit on number of emails you can send from your account, the limit applies to the following functions: “Reply”, “Forward”, “Test Emails” and “Share via Email in Publish”.

As you're using the "Share form via email" feature, each time you send an email it increase the counter, as you're a free account the limit is 20 emails per day, so once you've reached the limit the message "Oops.. Reached your limits"  appears. 

For paid accounts the limit is 1000 emails per day, if you need to send emails you will need to upgrade your account or you may also wait until this gets reset the next day (EST).

What I would suggest you is to send your form from your own email account so you avoid to reach your limits. 

Hope this helps.