
AutoSending Emails to Users with same message.
Note to other users who may have this question. It's useful to distinguish between marketing and transactional emails, the latter category referring to operational emails like purchase receipts, digital product delivery, etc...
And if doing marketing, it's further important to distinguish between outbound and inbound, that is emailing people that never gave you their email, vs people that explicitly signed up.
The vendors and techniques for all of these will differ quite a bit, you don't want to use outbound marketing resources for sending transactional email as that will cause the emails and perhaps the whole addresses and domains being marked as spam more often.