What causes problems with smtp yandex?

Question

OpenSSL

There was a following problem:
There is a mailbox on Yandex with a domain name.
I can not send a letter from it programmatically.
I check in the terminal: openssl s_client -connect smtp.yandex.ru:465 I go through
authorization, fill in MAIL FROM and RCPT TO, and then, when I enter "DATA", it displays: "503 5.5.4 Bad sequence of commands.".
Actually, it's the first time. The most important thing is that everything is sent well through the python script.

Answer 1

it means that not all headers can
be traced, I won’t tell you, everything is not for encrypted ,
unless you look at how the library works

Answer 2

openssl s_client -crlf -connect smtp.yandex.ru:465