I have a VPS on which I installed CWP. In Roundcube, no emails are sent to Gmail emails. Everything I did didn't work. Please guide me so that I can send emails to Gmail accounts. So far, no spam message has been sent to Google to block me.
Message:
This is the mail system at host s1.serveri.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
<[email protected]>: host gmail-smtp-in.l.google.com[74.125.140.26] said:
550-5.7.1 [37.32.20.20] The IP you're using to send mail is not authorized
to 550-5.7.1 send email directly to our servers. Please use the SMTP relay
at your 550-5.7.1 service provider instead. Learn more at 550 5.7.1
https://support.google.com/mail/?p=NotAuthorizedError
r8-20020a05600c35c800b003fba1bde3e5si3945777wmq.188 - gsmtp (in reply to
end of DATA command)