You should definitely not use "SomeTableauServerUser" as the user responsible for generating the trusted tickets. That's just a placeholder. Put a real user in to fix the -1 issue.
Now, the next issue is your SMTP server. Can you share a picture of your config\vizalerts.yaml file? Or share it as an attachment? Either way be sure to strip out anything sensitive, first.
Thank you for the reply and update Matt C.
I will get the SMTP info to you as soon as possible.
Again, when I swap the placeholder username and password I am no longer receiving the trusted -1 error but instead
'Email failed to send: [Errno 10061] No Connection could be made because the target machine actively refused it.'
Thank you for pointing us in the right direction Matt.
We started playing around with the SMTP configuration in vizalerts.yaml and was able to generate the alerts finally.
That 'V' Cyrillic also trigger it for us.
Glad you got it working!