Postfix emails are sent in groups?

if you want to use ubuntu + postfix + laravel to do a mass email system.
but if there are too many emails, it will be 504 if you send them for a while. This problem can be solved with set_time_limit (0)
but feels too inefficient.
is there any other way to directly give the recipient address to postfix at once?
ask postfix to send more than one email at a time?
ask experienced friends to coach

Mar.21,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e9f557-1a4c.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e9f557-1a4c.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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