Question : The recipient's mailbox is full and can't accept messages now.

We receive a message when sending an email to a manager that has about 3GB in his mailbox...

"The recipient's mailbox is full and can't accept messages now. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or contact the recipient directly."

Where is this setting found? The mailbox refers to "Use Mailbox Database defaults"

Is this under the Stroage Limits on the storage group?

Issue Warning:     1991680 KB
Prohibit Send:     2097152 KB
Prohibit Send and Receive:     2411520 KB

Whats the norma here? Do people usually up that limit or just have the users maintain a smaller mailbox? Issues with larger mailboxes stored serverside?

Thanks in advance Gurus :)

Answer : The recipient's mailbox is full and can't accept messages now.

Just re-read the size of the mailbox.
There is a 2gb limit if you change it through either GUI

you can follow these instructions to increase it: http://www.petri.co.il/setting_mailbox_limits_over_2gb.htm