How to fix error after installing postfix&dovecot?

Question

Nginx

Hello.

I ’ll immediately show what error we are talking about (I didn’t write about the red / green lock in the topic :) )


I have a VDS on timeweb, I decided to set up mail, I used this guide . I installed postfix/dovecot/postfixadmin.

Sending letters works in a peculiar way:
For Yandex : but when received in Yandex mail, a "red button" flaunts with a warning: "The letter contains incorrect or fake information about the sender. Also, someone could change the text of the letter after it was sent."
At Google : the letter does not come at all when you try to send, you immediately receive a notification that the sending was not successful (I look through the s-nail)


I will briefly describe what I did:
1. Created a subdomain: mail.linguacoder.ru (+ received a certificate via cerbot)
2. Added an MX record in the linguacoder.ru domain 3. Installed 0 mail.linguacoder.ru
postfix/dovecot/postfixadmin according to the guide

I've been trying for half a day and without success, I would be very grateful for help or advice . I haven't dealt with mail settings before, but I really wanted to figure it out.

PS Sending letters was done by the command:

cat ~/test_message | s-nail -s 'Test email subject line' -r [email protected] [email protected]

I tried to use mail.linguacoder.ru and linguacoder.ru as the sender's domain - the error does not go away

Answer 1

Good afternoon, now you can in order
1 You need to align HELO and rDNS. In my opinion, this is the most important, as I wrote in the comments.
2. SPF - "v=spf1 redirect=_spf.timeweb.ru ip94.228.118.106 ~all" is incorrect. The redirect operator redirects to the timeweb entry and nothing is read further. Correct - "v=spf1 include:_spf.timeweb.ru ip:94.228.118.106 ~all" or even "v=spf1 include:_spf.timeweb.ru a ~all"
3. DKIM and DMARC are needed
4. With blacklists, this IP is not particularly good