You can definitely connect your Apple Mail account to Nimble via IMAP. Take the following steps to connect:
In Apple Mail, go to Preferences >> Accounts.
Copy down your email account information and translate it over to Nimble.
(Please note when Apple's two-step verification is on, it may block Nimble from accessing your account).
Once your have your IMAP credentials, log into Nimble and visit the Settings >> Networks & Imports page. From here, you'll be able to connect the account via the IMAP connector. Learn more about connecting to Nimble via IMAP here.
If you have any questions, please write us at firstname.lastname@example.org, initiate a chat from this FAQ, or join one of our Nimble Onboarding and Best Practices sessions, held every weekday at 9 AM PT.