Before we go any further we strongly advise that you connect and verify your BUSINESS DOMAIN and send with a custom email addresses on that domain. If you are using a Gmail or Outlook integration consider switching this over as it is more reliable - you can read how here: http://help.bonjoro.com/en/articles/2850427-send-messages-from-your-email-with-outbound-email-addresses
Making sure your Email is squeaky clean
The world of email deliverability is a complex beast - luckily the folks over at Mail Tester have made this nice and easy to navigate.
Its healthy to give your Company emails a vetting every few months, just to check you're getting maximum deliverability, not just for your Bonjoros but for all email and mail campaigns.
NOTE: Again, try connecting and verifying your BUSINESS DOMAIN. You have complete control over the rating of your own domains, whereas Microsoft or even Gmail addresses are dependant on shared servers and are usually not as strong.
To check out your mail rating head to https://www.mail-tester.com/
They'll not only give you a rating, but measurable steps to improve this