Authentication/SPF or DKIM Issues

[Scott Green]

Hi Guys,

I have been trying to figure out our issue for months:

This is the mail system at host smtp.cloudplus.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

<as*****@gmail.com>: host gmail-smtp-in.l.google.com[142.250.4.27] said:
550-5.7.26 This message does not have authentication information or fails
to 550-5.7.26 pass authentication checks (SPF or DKIM). To best protect our
users 550-5.7.26 from spam, the message has been blocked. Please visit
550-5.7.26 https://support.google.com/mail/answer/81126#authentication for
more 550 5.7.26 information.
63-20020a630742000000b003f9cde547fasi22049254pgh.631 - gsmtp (in reply to
end of DATA command)

[Luke Briner]

What exactly are you asking? The message says that your mail fails SPF or DKIM so have you set them up but they don't appear to work or don't you know what those things are?

SPF is an absolute minimum for any server to send mail that won't be rejected. DKIM is pretty much also mandatory now as well as even with both setup, some providers will still drop your mail so if you haven't set them up, it is unlikely to end well.