How to increase email attachment size

[bmaple]

Two questions:

Has anyone increased email attachment sizes in this version of Plesk either server wide or per domain? If so, where is it?

In looking at the reports for each domain, we have noticed that the mail space total showing on the report does not agree with the detail total when each email account amount is added together. Has anyone else noticed this and does anyone know if the total includes additional information.

Thanks for any help.