As for the fact that your server is blacklisted, it really does not matter how much you send “at a time” it is more “who you send them”. If you send them to a user who does not want them, and they inform you of spam, then you will undoubtedly be blacklisted by one of the many DNS blacklist sites.
, , , " ", , , .
, , . , , IIS.
. (, ActiveMQ RabbitMQ), , , Windows . , .., , , ( ).
FIFO, , datestamp SELECT TOP 10 * FROM OutgoingMail ORDER BY datestamp ASC ( ), , .
Asynch , , IIS - , , .