Why is my Apple Watch not syncing emails?

When an Apple Watch is connected to either wifi or Cellular and not paired to an iPhone (both my Ultra 2 and Series 7 Apple Watches), new emails can no longer be received or sent, received emails are no longer listed or randomly disappear when attempting to refresh and new emails cannot be composed (the following error message is displayed - "Unable to Send Message - No email accounts available to send message"). This bug has been present in both Watch OS 11.0 and 11.1. This bug occurs when using 3rd party email accounts (e.g., Hotmail and Optimum) and iCloud email accounts. My friend has also experience this problem on his Apple Watch Series 7. Resetting the Apple Watch did not resolve this issue.

[Re-Titled By Moderator]