Database Mail (DBMail) in SQL Server is a feature that allows you to send emails directly from SQL Server, but it has limitations when sending a large volume of emails. The issues you’re experiencing with DBMail not being able to send massive emails could be due to several factors.
DBMail relies on the .NET Framework’s SmtpClient class, and any issues with this underlying component could affect DBMail’s functionality.
The SmtpClient class implementation pools SMTP connections so that it can avoid the overhead of re-establishing a connection for every message to the same server. An application may re-use the same SmtpClient object to send many