FBMail simply attaches to
1..n databases on a server, once attached it
selects all email's that need to be sent using a
stored procedure (FBM$EMAIL_GET), each record is
then converted to an email and sent to a
recipient. Once sent another stored procedure
within the database is called (FBM$EMAIL_SENT) to
indicate that the email was sent. If there
was a problem sending the email then another
stored procedure (FBM$EMAIL_INC_TRY) is called,
this updates the try count within the database.
Attaching to the database is done via the
Scheduler (windows) or as a Cron job (linux/unix).
Typically the php file "FirebirdEMail.php" would
need to be run about every 5 minutes.