This is a server that I use personally. It is not an open relay and sends email only from me. I have checked the outgoing mail logs and there is no way, not a chance, that there has been spam from my domain to any gmail accounts.

Google, I don’t understand why you’ve blocked me from sending email through my server from sending email to gmail accounts. Perhaps the IP address was used by a spammer in the past, but that must have been years ago. I don’t understand, either, why you make this form (https://support.google.com/mail/contact/msgdelivery) so difficult to find and fill out; why, for instance, you ask for ‘results from your tests’ and then limit the field length so that is impossible to provide those results.

I have now done everything within my power to ensure that my server cannot be seen as a spammer. I have set up reverse DNS records so that the IP address (***.***.***.***) correctly resolves to the hostname (******.***). I have added an SPF record for the site. In fact I have completely complied, always, with your “Best practices for forwarding emails to gmail” (https://support.google.com/mail/answer/175365?hl=en), and more recently with your “Bulk Senders Guidelines” (https://support.google.com/mail/answer/81126?hl=en) despite the fact that I am clearly not a Bulk Sender.

Please, at least, remove my server from your blacklist and allow the limited number of your users that I wish to contact to receive my emails.

Please also fix your form. And for pity’s sake please fix your 550 response so that it guides server admins to the form rather than requiring them to trawl the internet in search of it. I’d like to suggest, furthermore, that it’s not reasonable to blacklist a server and return SMTP 550 responses, without allowing the server administrator some means of discovering why their server is blacklisted.

Thankyou.

After submitting the form, this text is displayed:
Thank you for your report. We will investigate this issue and take the necessary steps to resolve it. We will contact you if we need more details; however, you will not receive a response or email acknowledgment of your submission.

… so, I can’t even expect a response? Lift your game, Google. Lift your game.

Edit 17/July/2015: After having avoided the problem for some time by (a) occasionally using a different mail server and (b) not emailing Gmail addresses, I finally figured out the problem – after looking at the Postfix logs and noticing that the IP address for the Gmail relay was an IPv6 address, I re-configured Postfix to contact Gmail servers only via IPv4. Hey presto, it worked! It seems that I had reverse DNS for IPv4 but not IPv6, and the lack of reverse DNS is enough to make the Gmail relays refuse to accept mail.

I wondered about this. I had SPF set up and surely that make the reverse-DNS check unnecessary? Of course there is always the following scenario:

• I gain access to a mail server through which I can route mail (maybe it’s an open relay, or maybe I get access via some other means);
• I set up a domain name, and specify (via an SPF record) that my relay is used to send email for that domain
• I spam away.

While this is certainly possible, it also seems to be easy to deal with, because it requires the spammer to purchase a domain and, given that emails can be verified as “originating” from that domain due to SPF, the domain can just be blacklisted. In any case I would think that the 550 response from the Gmail relay should include information on exactly why the message was refused, which would have saved me a lot of trouble.