Why doesn't devise want to send emails?

Question

Ruby on Rails

Devise from the seller does not want to send confirmation emails to mail.ru, gwu.edu did not find others yet. Has anyone encountered a similar problem?
I tried to test from the console like this:
ActionMailer::Base.mail(from: "[email protected]", to: "[email protected]", subject: "Test", body: "Test").deliver
It works.
ActionMailer::Base.mail(from: "[email protected]", to: "[email protected]", subject: "Test", body: "Test").deliver
Doesn't reach for the life of me.
There are no errors.

Answer 1

The sender's address must exist. He exists?
It just might be a problem in some cases.
Are you using the sendmail method? If yes, then as an option - test smtp. Although, I have ActionMailer and everything sends fine with sendmail.

Answer 2

Look at the mail.ru box in the Spam folder