New answers tagged gmail
This would appear to be due to the emails being detected being sent as a relaay instead of from a correctly configured SMTP server. The best option is to configure your PHP.ini file to use SMTP and to use your gmail server for SMTP and then use the PHP mail() function to avoid this error in the future.
Google not only depends on third party blacklists but also maintains their own internal blacklist. To remove your domain / IP from gmails blacklist you can use the form located at https://support.google.com/mail/contact/msgdelivery to report the issue and get it dealt with but Google may not automatically remove the blacklist entry depending on what Google ...
You can increase your ranking by adding a Sender Policy Framework to your domain. See:- http://www.openspf.org/SPF_Record_Syntax
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