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Were you able to recall the error message to why the emails landed in the bounce list? I have checked the said email addresses and so far all three are not in the bounce list.
On basic overview, emails land in the bounce list because your mail server rejected the emails from JotForm with the corresponding message as to the cause why they're not accepting the email. The logs that goes with the bounce back is the same logs given by your mail server.
One way for your email addresses to absolutely receive email alerts from JotForm is to ask your email service provider to whitelist the IPs found from this guide: https://www.jotform.com/help/145-Whitelisting-JotMails-IP-Addresses
You can also read on more information on preventing emails from landing to the bounce list from this guide: https://www.jotform.com/help/208-How-to-Prevent-Email-Bouncing-Related-Issues
In any case, if you have questions, please let us know.