What mail service / smtp to choose for sending emails from an online store (150k letters per month)?

Question

Email Marketing

There is a need to choose a mail service that works well with Firebase Functions .

What do you think is the best service/smtp/mailer to use for 5k emails a day?
I would like it with good documentation and the ability to use it as an API called from Firebase.
If you need to write some kind of API proxy - no problem.

Who would have thought it would be such a headache.
What I tried superficially:
- I tried Sendgrid and got a block without explanation, testing and development got up.
- Mailchimp looks like a marketing tool, not a mailing API.
- Gmaila very strange quota, somewhere it says that it is impossible to send more than 3k / day, but somewhere that 10k / day is a free limit.
- I was looking for hosting in conjunction with SMTP - I did not find separate descriptions of the STPM settings. Most often, they suggest using the PHP mail function without any additional information (maybe I didn’t look for it well, because I just ran around the places that send letters).

PS
The base is white and does not require a temporary solution, with a buffer of 100-200 emails per day for tests.
But, I would like not to catch a ban during development.

Answer 1

All SMTPs keep track of the reputation of their IP addresses. And when the norms for clicks on spam are exceeded, they are immediately blocked. The norms are different for everyone, from 0.1% to 0.65%. And if the mailing goes through databases collected on the Internet, the number of clicks is now 2-5%. So it all depends on the base. But if the base is white, there are options. Read, at one time briefly analyzed all the options
https://7fk.ru/nastroyka-smtp/

Answer 2

Install a virtual server, raise smtp on it, specify your server in the MX record of the domain, also do not forget to specify spf, DKIM, DMARC in the zone settings.
True, if you engage in spam, you will still be blocked.
And don't forget about the rules for writing mailing lists. Required 2 formats (text / html), be sure to link to unsubscribe, less, but better in general, the complete absence of links to external resources (pictures, etc.), and God forbid - JS.