Exact same problem here! 
E-mail used to work fine before upgrade, now “Error:SMTP connect() failed.”
The mail server is local, 192.168.0.14, doesn’t require authentication for local senders, no SSL/TLS. We run our own SMTP server (logs don’t show any connection attempt at all).
Hopefully someone figures this out fast, as it breaks our CRM big time! (All our workflow events send out E-mails to people to keep projects moving along)
-RoB-