One day you wake up and find out that your emails and events are no longer logging to Salesforce automatically like they used to, it's likely because your email and calendar accounts have disconnected with Salestrail.
Unfortunately, at the moment, Salestrail hasn't been able to notify users when any of your connection is interrupted, therefore, please take the initiatives to check once in a while, especially if you are using Outlook.
Note: If you update your email and calendar credentials, then you MUST reconnect them to Salestrail.
To check your connection, simply open Salestrail app > Settings > Email Settings and Event Settings. If you see Log in, that means it's disconnected and you need to re-connect.