Suddenly, I cannot send mail via Thunderbird. Settings are defaults, security is set to minimum, and I'm getting timed out errors from the outgoing server. Same issue with two different Macs (Mini and MB Air), both running Mac OS Sonoma. Changing ports has no effect. Can send mail from the same Spectrum account via my iPhone, and Spectrum's webmail works fine, so the problem seems to be a new incompatibility of Spectrum with either Thunderbird or Mac OS.