Mail Connection Issues Since Last Security Update 2/4/2020
MacBook Air 2011, High Sierra. Since last security update Mail will not connect with Yahoo or GMail servers in standard mode. However I can connect in Safe Mode. Firewall is disabled. I have removed and tried to re-connect accounts (only possible in Safe Mode). I removed expired certificates from Keychain. Seeking other suggestions as to what changed and how to re-enable mail in standard mode,. Thanks in advance.
MacBook Air 13", macOS 10.13