Your students' email accounts are available in WebCentral in the My Teaching Schedule channel.
You should see the list of your sections if you are teaching during the current semester. Just use the View Roster button to go into a specific course section.
You will see the PREFERRED email accounts that students have registered in BC WebCentral or other Brooklyn College online systems.
To see student phone numbers and official campus email accounts (cloud-based Office 365 "bcmail.cuny.edu" accounts), use Print (PDF) or Spreadsheet buttons.
Downloaded rosters include your student's preferred and Brooklyn College email accounts and phone numbers (as of March 13, 2020).
The CUNYfirst Faculty Center recently updated the Class Roster to include CUNY Login information for students.