This is a staging table with an entry for each message of each mailbox currently being imported in a controlled way by the user interface. The contents are meant to be deleted soon after the import is complete.
Structure of import_message
import_id
int
REFERENCES
import_mbox
mail_number
Number of the message in the mailbox starting from 1.
encoded_mail
The actual message content.
apply_filters
character
'Y' if the filters for incoming mail should be applied when importing this mailbox, 'N' or NULL otherwise.
status
smallint
Status of the import for this message. Values are 0=new, 1=imported, 2=cancelled.
mail_id
int
The ID of the message once it's imported.