How to ensure that letters from our forum do not fall into Google spam?

Question

Google

Good afternoon! There is a mail server serving several domains.
Through it, one forum sends letters confirming registration. For some reason, these emails end up in the spam folder of google mailboxes.
A very important point: sent letters from other domains do not end up in the Google spam folder (including newsletters based on more than 150k subscribed users). The server uses dkim, spf.
Tried to change a bit the text of the letter and the subject - zero result.
I could not find in Google how to write to them in support.
Has anyone had experience solving similar problems?

Answer 1

X-Mailer: IPS PHP Mailer - For most spam filters, this will be enough to identify it as SPAM. Since sending by PHP script (from the point of view of the spam filter on this field), it is massive, and therefore 99% spam.

Answer 2

As an option for a simple solution to the problem, you can try using services like mailjet , elasticemail.com

Answer 3

letter headings, to the studio, from the Google box.

Answer 4

check spamhouse, spamcop.

Answer 5

Try sending an email via telnet:

telnet server_address smtp
HELO domain.
MAIL From: [email protected]
RCPT To: [email protected]
DATA
Subject: hello
hello world
.
quit

This will give you a test without unnecessary headings and text.
( Description )
charset=utf-8- without quotes

Answer 6

Have you looked at your IP history in services like spamhaus and the like? Maybe malicious spammers used it before?
Is the reverse DNS of the server from which emails are sent pointing to your domain, or to something obscure like 19393.28.clients.someservice?
The reason (apart from technical issues like reverse DNS and SPF) can also be in the content of the letter, text, links, their number and where they lead.

Answer 7

Likewise. Registration from our forum gets into spam in Google boxes. I don't know what to do other than notifying me when registering.

Answer 8

Attach DKIM to your mail server
support.google.com/a/bin/answer.py?hl=en&answer=174124&topic=2752442&rd=1

Answer 9

I use sending through the regular postfix settings from php. 4k emails per day. Nothing gets into spam (knock on wood). The only thing he did was correctly registered the PTR record and MX points to this PTR record with the last metric for this domain.
But I know for sure that services like gmail, mail.ru and the like very rarely look at PTR, since this is a very difficult network operation by Google standards, for the amount of spam they receive. I think if you write a correct unique message, Unique title! Exclude pictures and html at the first stage, or at least make it very small, and also add unsubscribe information with a link or instructions to the text - then everything will be fine for you!