Google blocking emails

If I compile Postfix Mail Server with:

AntiSpam/AntiVirus (recommended):
ClamAV, Amavis & Spamassassin, Requires 1Gb+ RAM

Google blocks my emails with the error below, if I remove it my emails can be delivered.

I have added the Google authentication text to the DNS but that didn't help, (maybe I did it wrong)

It's strange that installed it fails with low reputation but removed it doesn't have any issue.

Anyone have this issue before?

-----------------------

This is the mail system at host server.mine.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

<clients@gmail.com>: host gmail-smtp-in.l.google.com[2404:6800:4003:c02::1a]
said: 550-5.7.1 [2001:c00:4618:2007:6a87:4eb0:3ca8:29d2 18] Our system
has 550-5.7.1 detected that this message is likely suspicious due to the
very low 550-5.7.1 reputation of the sending IP address. To best protect
our users from 550-5.7.1 spam, the message has been blocked. Please visit
550 5.7.1 https://support.google.com/mail/answer/188131 for more
information. u25si176943pfm.164 - gsmtp (in reply to end of DATA command)
Reporting-MTA: dns; server.mine.com
X-Postfix-Queue-ID: 39D5620B68DD
X-Postfix-Sender: rfc822; support@mydomain.com
Arrival-Date: Tue, 20 Feb 2018 21:44:57 +0700 (+07)

Final-Recipient: rfc822; client@gmail.com
Original-Recipient: rfc822;client@gmail.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [2001:c00:4618:2007:6a87:4eb0:3ca8:29d2
18] Our system has 550-5.7.1 detected that this message is likely
suspicious due to the very low 550-5.7.1 reputation of the sending IP
address. To best protect our users from 550-5.7.1 spam, the message has
been blocked. Please visit 550 5.7.1
https://support.google.com/mail/answer/188131 for more information.
u25si176943pfm.164 - gsmtpReturn-Path: <support@mydomain.com>
Received: from localhost (unknown [127.0.0.1])
by server.mine.com (Postfix) with ESMTP

"Our system has 550-5.7.1 detected that this message is likely
suspicious due to the very low 550-5.7.1 reputation of the sending IP
address."

I would start with checking that your servers ip isn't on any blacklists, then make sure your RDNS is correct and you have a valid hostname , add an spf record to ensure quality of your reputation

But then it would still be an issue when I removed ClamAV etc.

It turns out the issue was the SPF, I found it by sending an email to Yahoo and checked the header, which gave an error that the SPF error and couldn't be checked, which for Google this would give a low reputation.