Cannot verify server idemtity
The error messages show this is the problem dayznews.biz
iPhone 14 Pro Max, iOS 17
You may have a subscribed Calendar or a CardDAV account for Contacts or Calendars.
What happens when you click the "Details" on the error popup message (See the Pic below)
Best would be to Delete and Add the email account that is creating the issue.
You may also try changing SSL settings
Settings > Password & Accounts > [Select the Mail account} > [Tape on Account with the email ID} > Advanced > SSL Settings > [Disable]
Click <Account (in Blue)
Click on DONE (in Blue) when exiting in the previous screen