Solution
For this procedure will be needed two Python scripts:
list-accounts.py and cli2.py
The automation scripts available on our website to see the mailbox sizes of all accounts from a domain.
The scripts are available at:
https://www.axigen.com/mail-server/scripts/download/?tool=list-accounts.py
https://www.axigen.com/mail-server/scripts/download/?tool=cli2.py
Place those two files in a folder, and issue the following command in the directory where the scripts reside:
python list-accounts.py file=myaccounts.txt domains=your_domain_name registry=1 ms=1
The needed data will be found the the file named myaccounts.txt file generated as a result of this procedure.