Was getting lots of errors due to IMAP client being passed the wrong number of arguments. Something changed in core-2021.7.X.
Changing entry in manifest to "imapclient==2.2.0" fixed the problem
I also had this issue after updating core. For those not sure of process, make the edit noted above to custom_components/email/manifest.json then restart core to apply.
Was getting lots of errors due to IMAP client being passed the wrong number of arguments. Something changed in core-2021.7.X. Changing entry in manifest to "imapclient==2.2.0" fixed the problem