How to implement e-mail distribution on your own database?

Question

Email

Our company has a customer base - about 100,000 people.
It is necessary to organize an e-mail newsletter for our customers to inform them about the new promotion and discounts.
What software or service is better to use for this? I thought about Mailchimp / Unisender - but it turns out to be a little expensive, they gave me the task of finding a more economical solution.
A prerequisite is that our database does not fall into the wrong hands and that it is possible to receive a report on delivered / opened ones.
Thanks for the reply.

Answer 1

Try https://postmaster.yandex.ru/
There is delivery data there, as far as I remember there is no information about the opening - but it is logical to collect it yourself.
PS
Excellent report "Email-mailings for pros - common mistakes, what to improve, how to monitor" from Andrey Sas
habrahabr.ru/company/badoo/blog/228265