I only ask this because I am using IMAP and it shows zero bytes. Beinf IMAP it definitely is using.. 7GB to be precise but it shows zero.
Is thisbecause it was only designed to read Pop3 and therefor IMAp will show zero or is there a setting I can change in the config file?[forgive my ignorance]
Enclosed screenshot.
Thanks in advance.

Unlike the POP3 protocol, the IMAP protocol only returns the number of messages marked as UNREAD, it does not return the size of those messages.

You can check this by mousing over the Email Checker module. The line for the IMAP account in the balloon tooltip will only say 'X messages unread', while for a POP3 account it will say 'x messages, y bytes'.

The desktop version of the Email Checker module does not make this account-by-account distinction, it only reports the TOTAL number of unread messages and their sizes for ALL email accounts defined in the Email Checker.

It is interesting considering POP3 does not affect any server mail and IMAP is a direct copy of the server mail and will actually delete whatever you delete in your client etc.
So I would have thought that actual "size" of the mail would be more pertinent to IMAP.