Hi Katerina,
Yes, you're right. All communications should be done through Upwork before a contract is placed.
Client on a Business and Enterprise plan are permitted to request and share contact information and conduct interviews or pre-contract communications outside of Upwork’s platform. You can identify whether a client is Upwork Business or Enterprise by looking for the following symbol on the right column of the job post or in the search tile:
If you see a job or a profile that seems suspicious, you can report it to us using the flagging option. You can read more on this help article and also, please check out Tips to avoid questionable jobs. You might also want to check out the information here to learn more about staying safe on Upwork.
