SEND EVERY   A frequency can be specified in hours, minutes, and seconds in the format 'HH:MM:SS'.

When any user with SEND EVERY set is sent messages, all users with the same frequency are sent messages also. For example, all remote users who receive updates every twelve hours are sent updates at the same times, rather than being staggered. This reduces the number of times the SQL Anywhere transaction log has to be processed. You should use as few unique frequencies as possible.

SEND AT   A time of day, in hours and minutes.

Updates are started daily at the specified time. It is more efficient to use as few distinct times as possible than to stagger the sending times. Also, choosing times when the database is not busy minimizes interference with other users.

Default setting (no SEND clause)   If any user has no SEND AT or SEND EVERY clause, the Message Agent sends messages every time it is run, and then stops: it runs in batch mode.