Setting up your own email marketing service?

Question

Email

There is a need to organize your own email service (not spam)
There is a database of existing and potential customers of about 5-8 thousand, a small developing company, they need to be notified about news, promotions, new services, changes, reminders ...
But, this should be a correct mailing, not spam, with the ability to unsubscribe directly from the letter ...
There are no funds for paid services yet, and with your own service it is easier and there are no restrictions on the number of letters.
Help with advice, perhaps links to instructions and possibly free or open source projects ...
I would be grateful if you share your experience.
Thanks in advance!

Answer 1

sparkpost 100k per month for free
A small web application that uses an API service and distributes everything you need to a database of several thousand people.
It's nowhere cheaper

Answer 2

I understand that there is no cost at all. It probably won't work for free. You can, of course, but it is illegal, and if there are such services, then they are probably not very convenient. Can you elaborate on what you would like? And yet - "There is a base", what is it with you?

Answer 3

for starters
planning a mailing list server
how to properly run
opendkim or dkimproxy mailing lists