I have a private server which is also my and my families' mail server. For a few weeks now, Gmail is blocking mails from my server and I can't find out why. Google's documents and contact forms for this turned out to be dead-ends or blackholes, they never get back to me.
So, how can I contact Gmail regarding this? Preferably a human, of course.
I used to be able to send to Gmail in the past years, but starting almost a month ago all my mails are rejected with the following message:
Our system has detected an unusual rate 550-5.7.1 of unsolicited mail originating from your IP address. To protect our 550-5.7.1 users from spam, mail sent from your IP address has been blocked. 550-5.7.1 Please visit 550-5.7.1 https://support.google.com/mail/?p=UnsolicitedIPError to review our 550 5.7.1 Bulk Email Senders Guidelines. 132si3016603wmh.2 - gsmtp (in reply to end of DATA command)
Here's what I've checked and done so far:
- To the best of my abilities, I haven't found any malware on my server (ran chkrootkit as well).
- Traffic is as low as always and I haven't found anything suspicious in my logs yet.
- My server is not an open relay (I check using several online services).
- The server is only used by me and my family, only authenticated users are allowed to send.
- My server/domains are not listed in any DNSBL (I checked using www.dnsbl.info and others).
- My domains are listed in DNSWL.org.
- My domains are registered with Gmail Postmaster Tools. They are marked as Verified there.
- I have tried to contact Gmail twice using their contact form and provided the requested informations. They did not get back to me (the first time I wrote to them was 3 weeks ago, the last time several days ago).
- I did read the document on the page mentioned in the bounce and read the ones linked on that page, but they all are turn out to be dead-ends.
- In the Gmail Postmaster Tools, they link to a choose-your-own-adventure-style document for troubleshooting (it's also linked somewhere on the page from the SMTP error message). That also turns out to be a dead-end since I fulfill everything (with the sole exception that I don't have DKIM).
- I have valid SPF records for my domains, but no DKIM.
- The IP has a valid reverse DNS record (PTR).
At this point, I don't know how to proceed. There doesn't seem a way to actually contact a human at Google regarding this and I can't find out why my server is blocked by Gmail.
How can I proceed? What am I missing? Is there a way around this, for example a kind of relay service that I can use to get my mails from my server to Gmail?
Edit: I checked the Postfix logs for outgoing mails in the past few weeks and did notice there is backscatter from one account (the mail for that user is forwarded to another server which sometimes declines messages as spam that my system didn't catch). It happens about once every two days and always to the same address but of course I need to fix that. Other than that, the logs show no unusual outgoing mails. I did sign up for GSuite (the first two weeks are free) and sent a support request, let's see how that goes…
Edit 2: I did get a response from a human at GSuite support pretty quickly. After a few mails back and forth we had phone conversation. Essentially, the guy told me that unfortunately there's nothing he can do here (wrong department and no access to the necessary systems) but he'd want to try to help me anyway and forward my problem to someone else. That was on Friday, today's Tuesday and unfortunately nothing happened so far. Mailing still doesn't work, so it's another dead-end and I'll try to get someone else on the phone using http://www.wikihow.com/Contact-Google .