You can receive mail using i.Scribe using two methods. Manually by clicking receive mail on the toolbar or Mail | Receive mail. Or automatically by going into the options and on the POP3 tab set the "check every <field> minutes". The field being the number of minutes between checks. New mail appears in the "Inbox" folder by default and a "New mail" icon appears in the system tray. Clicking on this icon opens the first new mail in the inbox folder (or sub-folders). You can specify a non-default destination folder in the Pop3 options.
To send mail using i.Scribe can be done from the mail message by clicking send, by clicking send on the toolbar or clicking Mail | Send Mail. Sending sends all unsent mail in the "Outbox" folder. Once a mail is sent successfully it is marked as sent and placed in the sent mail folder. To resend a mail, move it to the outbox, open it up and click "send" again. It's that simple (try doing that in Outlook).
The progress dialog looks like this:
The lower "request abort" button will cancel the download in progress, causing the current email being downloaded to remain on the server and the batch to end. The button on the upper progress indicator will cancel the download after the current email has downloaded. However the initial connect can't be canceled. You just have to wait till it times out. Alternatively you can quit scribe, a dialog will display saying there are still taskes active, click "kill" to end these taskes immediately.
The client will attach to the server, query the server for the size and number of email still on the server and then present a list of items to you. Then by selecting the items and clicking "delete" or "download" you can decide how to process each email individually before you receive them. This allows you to skip large messages or delete them when they get in the way. The selected delete or download action is carried out when you click Ok. If an item hasn't been assign an action (delete or download) then it is ignored and left on the server. Beware that if you have the leave mail on server option set to on then you will see all the mail currently on the server not just the "new" mail. This is what the window looks like:
If your downloading mail and you notice a really huge email then cancel that download (the bottom "request abort" button on the progress window) and then open up the preview mail on server window to either download the email either side of the large one or delete the large email altogether.