CRM and Mail Licensing

CRM and Mail Licensing

Hello,

I have 10 employees in my company.
5 of them are going to use the CRM: Accounts, Oportunities, Tasks, etc.
5 of them are technicians that will use Zoho, Projects, Zoho Mail and nothing more. 

The problem is that the information of the customers will be on the CRM (Accounts and Contacts)
Technicians need to access to the customers information (Account and Contact) just to see information (address, telephone, etc) but they don´t need to go in depth (oportunities, quotes, etc.) and they don´t need to edit or modify anything inside the CRM, just view information.

Is it possible to buy 5 licences of CRM Proffesional and the Free plan of Mail?
If I do this, will the technicians be able to check (just view) the information of Account and Contacts of the CRM?

Regards,
Unai Mata