Allow Insecure Authentication in Mail

MacBook Air 13" M3 2024, Tahoe 26.1, Mail 16.0 This regards "allow insecure authentication."

I moved to a new senior residence that provides a building-wide internet, I'm told much like a hotel, that shows as "Unsecured network" in the Wi-fi drop down list. At a neighbor's suggestion, and as other neighbors have done, I installed a "travel router" to "piggyback" (neighbor's description) onto the house network, and it works ok and shows with the lock icon in the drop down list with the name of the router, a GL.iNet SFT1200. Here is the issue: before and after installing the travel router, I had not been able to send emails from my @Mac.com account in Mac Mail that I have used for years. However, I was receiving emails. In prior residences I have had FIOS, or Comcast routers, those typical for a home residence, with no problem. I search and drilled down into Mail account settings and eventually found the tick box next to "Allow insecure authentication" which was unchecked. So just taking a flyer, I checked this box, and then I was able to send emails. Question: is my email "system" now more at risk? If so, is there a better way to fix my problem?