If an email is auto-imported from a known contact but their latest job is in the Completed stage, the message will remain unassigned and appear in your 'No Job Assignment' sidebar list. A common case of this is a former client (with a completed job) emailing about booking you for a new job.
Emails Between Táve Users
Emails sent between two Táve users outside of Táve will not auto-import. While the two employees may be discussing something relevant to a job in Táve, they could also be discussing confidential information (i.e. salary, inter-office politics, juicy gossip), and therefore it wouldn't be appropriate to import those into a system shared by multiple employees. To import messages between two employees relevant to a job, simply assign the 'Import to Táve' label to the email in Gmail.
Adding Other Contacts Involved in the Email Thread
Any contacts involved on an email imported with Google integration that are not currently contacts in your Táve address book will not be automatically added to your address book for you. If you wish to add any new contacts to your account address book, on the email they're involved in, you'll click on the purple "Add contact to job" icon from the mail details popup. This will also add this new contact to the worksheet of the lead or job the email is attached to for you.