How to make a one-time mailing?

Question

Email

There are 500 addresses of people potentially interested in some highly specialized product.
You need to do a one-time mailing.
DKIM, SPF, static IP - everything is there.
Do I need to make mailing headers, an "unsubscribe" button when the mailing is one-time?
The content is minimally spam, without the words "free", "promotion", without pictures, there are no heaps of links.
Each user is treated by a nickname.
A letter from [email protected], the subject contains a nickname.
Yandex mail for domains is connected to the domain.
What is the chance of such a message getting into spam? What can be done to reduce this chance?
At what intervals to send messages?

Answer 1

Sending from [email protected] is a bad idea since. marketing, it is better to send from personal or special addresses (such as [email protected]) and be sure to indicate the sender's name too.
And so you are still solving a problem that you do not have. Send first from your server, look at the result. And it's better not to bother with the html-letter, send it from a personal box.
If you want to do it "correctly", then use one of the services for mailing lists, you will have to put an unsubscribe link there.
Here are services with a free plan (but they all have pre-moderation before sending), which is enough for you:
https://sendpulse.com/ru/
https://www.mailerlite.com/ru
mailchimp.com