What is The Mail Stream
The Mail Stream is scalable. It delivers millions of emails per month. But it's primary purpose is to protect everyone from email abuse, which is part of the reason why you get great delivery.
Providing you stick to best practice when sending out emails and you're only sending them to people that want or expect them, everything will be fine.
Mail Stream will only let you send millions of emails when you have a good trust score and reputation.
You start with a neutral reputation! and a neutral reputation.
It's up to you to build up trust and maintain a good sender reputation.
Everybody starts with the capability to send a maximum of 300 emails a day for the first few days.
Providing a percentage of the people you send to open, read and click (your engagement rate), your daily capacity will increase.
After your first week you should be close to the 1000 emails a day capability.
Think logically, neither Gmail, Outlook or any companies that use commercial email filtering and protection services are going to let someone they have no measure of, blast their cutomers with emails.
Depending on your engagement rate you could be at the 5 - 10K daily capacity in your third week .
Remember it's simpler to build trust than it is to rebuild it if you lose it. And it's very easy to lose!
Mail Stream will block your outbound mail if it detects or thinks you are sending unwanted emails.
If this happens it's not the end of the world for the 'first offense'. Be aware though that this can cause anomolies in open rates etc.