Cannot send mail

Hi, when i try to send mail it write that i cant. In log is this:
Release mail 1A9A54
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 SMTP-OUT:00000006: BDAT chunk rejected with message: 5.7.26 This message does not have authentication information or fails to 5.7.26 pass authentication checks. To best protect our users from spam, the 5.7.26 message has been blocked. Please visit 5.7.26 https://support.google.com/mail/answer/81126#authentication for more 5.7.26 information. v18si361746edx.378 - gsmtp
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 SMTP-OUT:00000006: Set recipient kabelka123@gmail.com state to RELAY ERROR
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 SMTP-OUT:00000006: Delivery attempt completed for mail 1A9A54; schedule for cleanup
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 SMTP-OUT:00000006: Set mail state to SENT
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 SMTP-OUT:00000006: Disconnected from 108.177.126.27
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 PROCESSING:001A9A54: Shepherd thread received signal for cleanup
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 PROCESSING:001A9A54: Mail removed from queue
2020-06-17 19:17:40 +0200 08 WIN-0Q5BA0K4N16 PROCESSING:001A9A54: Set mail state to REMOVED
`

Hello,

According to the log records the message was rejected by Gmail with a permanent error 5.7.26:

SMTP-OUT:00000006: BDAT chunk rejected with message: 5.7.26 This message does not have authentication information or fails to 5.7.26 pass authentication checks. To best protect our users from spam, the 5.7.26 message has been blocked. Please visit 5.7.26 https://support.google.com/mail/answer/81126#authentication for more 5.7.26 information. v18si361746edx.378 - gsmtp

more information regarding the cause is available at the link provide by gmail - https://support.google.com/mail/answer/81126#authentication -

## Make sure your messages are authenticated

Authenticated messages:

* Help protect recipients from malicious email, like phishing messages.
* Are less likely to be rejected or marked as spam by Gmail.

These authentication methods are set up at your domain provider. If you use a domain hosting service or an email provider, use the provider's instructions for setting up authentication. Set up authentication for each of your sending domains.

To minimize the chance that your messages are marked as spam, set up these authentication methods:

* Publish an [SPF record](https://support.google.com/a/answer/33786) for your domain. SPF prevents spammers from sending unauthorized messages that appear to be from your domain.
* [Turn on DKIM signing](https://support.google.com/a/topic/2752442) for your messages. Receiving servers use DKIM to verify that the domain owner actually sent the message. Important: Gmail requires a DKIM key of 1024 bits or longer.
* Publish a [DMARC record](https://support.google.com/a/topic/2759254) for your domain. DMARC helps senders protect their domain against email spoofing.

For SPF and DKIM to authenticate a message, the message **From:** header must match the sending domain. Messages must pass either the SPF or the DKIM check to be authenticated.

Ensure that your domain has a proper SPF TXT record in DNS and also that messages are DKIM signed. Information how to set SPF and DKIM are available at:

https://www.axigen.com/documentation/spf-dkim-dmarc-p3277033

Regards,
Florin