Can't send mail in Mail app in Ventura

After my 27’ iMac automatically downloaded and installed Ventrua 13.6.1, it became totally inoperable. After several calls with Apple support, I was told to reinstall Ventura. I did with the same result. I was finally told to do a clean install and then restore using my time machine backup. I then could not restore using time machine although it was recognized. The advisors had no idea why that would happen. After several more calls, I was told I would have to restore my files manually which I did with help from Apple support.  All seemed well except I could no longer send mail. A “senior” support person tried to help through screen sharing but to no avail. He said he would create a “ticket” and get back to me at a time he gave me the following day. I received no call at that time and called  2 hours after the scheduled call. I was referred to another “senior” support person. She advised me that the “engineering people” were now only supporting Sonoma, and there was nothing more Apple could do. I was told to use the web based iCloud mail! I subsequently did receive call from the advisor who created a “ticket”,  and he repeated the same information. Very disappointing.

After Ventura 13.6.1 update Apple Mail app keeps asking for password from my email accounts with the local ISP. Gmail is working fine. Anyone else have a similar problem.