What are the practices you are using with respect to email user names to differentiate between employees and consultant/temps in order to limit co-employment risks associated with consultant/temps inadvertently being included in all company meetings, communications, etc.?

Similar to what Yvonne posted - using an identifier like john.smith.ctr@xxxx.com

I've seen unique email addresses used - ie c-johnsmith@xxxx.com.  Then it is also easy to find them all when IT is asked.  

We use to give special named accounts for external, and consultant personnel.  The Full-time employees are the only ones that uses the corporate standard email addresses/network accounts.

We address co-employment risks by using a special subdomain for all mailboxes related to external, temporary, and consultant personnel. This approach makes it easier to distinguish them from full-time employees, and helps to filter them out from general company meetings or communications. 

Additionally, using a subdomain allows for more straightforward implementation of Role-Based Access Control (RBAC) and other types of filtering and differentiation querying across various components of our user and identity management ecosystem.