MDR Silently Fails if default folders do not exist

[Jason]

Reproduction:

1. Installed Haiku Alpha 1.
2. Setup MDR
3. Symptoms:
   1. Default Mail folders (inbox and out) did not exist under ~/mail
   2. MDR would not send email without said folders
   3. MDR displayed error message for ~/mail/inbox not existing
   4. MDR did not display error message for ~/mail/out existing
   5. Mail would not send without ~/mail/out folder
   6. Outbox mail would be created in ~/

Workaround:

• Create 'inbox' and 'out' in ~/mail if they are not created upon Alpha 1 install.

Expected MDR behavior:

• create any missing folders that exist in its configuration if the folders do not in fact exist.
• give an error message if the OUTBOX folder doesn't exist.
• NEVER put mail files in OTHER folders if the folders in the configuration do not exist.

[Jason]

CORRECTION: ~/Mail should read ~/mail