Emails no longer open on my iMac running Monterey

My 27" 2015 iMac running macOS Monterey, I had the following problems:

Mail: When I click on Mail in the Dock and it opens (after about one and a half minutes) , I can click and read existing emails. However, as soon as Mail starts downloading new emails, when I click on them to open them and read the text, they don't open. Not only do the new emails not open but the existing emails stop opening. It takes at least six and a half minutes until I can open any of the emails showing in mail, and that includes any emails in the Junk section of Mail.

Safari: It now takes at least a minute and 45 seconds for Safari to open after I click on its symbol in the dock.

I have not been able to find anything in either Mail or Safari Preferences that might be a factor in these problems. System also runs slow.