I am having the same problem.
I have an “Arduino Uno Wifi Rev2” board.
I am trying to use Gmail but I have also tried Yahoo and Office365.
I have confirmed SMTP works on my laptop by creating a quick program in Visual Studio 2019 (Windows 10). In that test program, I am unable to send emails on port 465 but emails do work on port 587. This is the case with gmail, yahoo and Office365.
I have used the same settings on Arduino but consistently get a “timeout” when trying to send an email. WiFi connects fine.
I did have to change the includes to this for your basic send example:
#include <EMailSender.h>
#include <WiFiNINA.h>
#include <UIPEthernet.h>
My constructor is:
EMailSender emailSend(“[my email]@gmail.com”, “[my password]”, “[my email]@gmail.com”, “[my name]”, “smtp.gmail.com”, 587);
Thanks!