Acronis True Image 2016: E-mail Notifications to Gmail Fail with "Authentication failed"

Symptoms

1. You set up e-mail notifications to Gmail.
2. Sending e-mail notifications fails with:
   Authentication failed
   

Solution

1. In your Gmail settings turn on Access for less secure apps:
   
2. In Acronis True Image settings specify:
   SMTP server: smtp.gmail.com