How to send out 3500 emails so they don't end up in spam?

Question

Email

It is necessary to send 3500 letters to the addressees. Perhaps some are invalid.

These emails must not end up in spam.

How to do it for minimal money?

What trusted service to use to pay for actually sent letters, and not buy tariff plans for overdoing emails?

Answer 1

You can pay for the required number of letters on the UniSender service.
Another option is SendinBlue. There, on a free plan, you can send 300 emails a day.
Well, getting into spam - there are many factors, if your recipients do not click on spam, if you set up the domain and service normally, do the letters themselves correctly - everything should be fine.
And it is better to clean the database from invalid before sending

Answer 2

MailChimp