Undelivered Mail Returned to Sender issue

SYSTEM INFORMATION
OS type and version Ubuntu 22.04
Virtualmin version Latest

Can anyone know what’s the issue here?

This is the mail system at host server.domain.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<abc@gmail.com>: host gmail-smtp-in.l.google.com[142.250.27.26] said:
    550-5.7.26 This mail is unauthenticated, which poses a security risk to the
    550-5.7.26 sender and Gmail users, and has been blocked. The sender must
    550-5.7.26 authenticate with at least one of SPF or DKIM. For this message,
    550-5.7.26 DKIM checks did not pass and SPF check for
    [vmi1466349.contaboserver 550-5.7.26 .net] did not pass with ip:
    [11.111.11.111]. The sender should visit 550-5.7.26
    https://support.google.com/mail/answer/81126#authentication for 550 5.7.26
    instructions on setting up authentication.
    c1-20020a170906528100b0098d2f716c75si13079619ejm.597 - gsmtp (in reply to
    end of DATA command)

I add record for SPF and DKIM, but don’t know why i’m getting this issue

This is all related to your other thread. Have you added spf to where ever your dns is handled. I know the other thread is DKIM. Bottom line. It sounds as if you aren’t adding them correctly to where your DNS is being served from if nobody sees them.

Yes i added SPF correctly when i’m sending mail from my self then it send easily to my gmail account but when email send from wordpress for login with OTP then it’s Undelivered

You need to change the PTR in your contabo account to reflect your server hostname.

Yes done now its fixed, Thanks for the help

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.