Exporting mailbox information to CSV for one particular domain or one OU

Hello,

I have an Exchange 2013 server which handles email for about 5 different domains.
I need to export to PST all mailboxes for one of these domains.

Part 1.
1.I would like to first gather the following in CSV: Name of User | Email Address | Mailbox Size
2.I've tried various commands exporting to details to CSV, but when I open the CSV, I find that all the data is in a single cell rather than separate columns.  Can you furnish the appropriate command to address this issue?

Part 2
1.Also is it possible to export this information only for mailboxes with the particular email domain (all users whose email address ends with domain2.com?
2.Can it export information only from one particular Organization Unit?

Thanks in advance.

Regards,
Real-Timer