Gmail and other private servers mark legitimate email as SPAM

Question

The mail server configuration is driving me crazy. Emails sent from my own private server are being banned, again by Gmail and other private servers.

I checked gmail headers and SPF, DKIM and DMARC pass the exam. Attached the headers of a blocked email sent and blocked by gmail (sent to the spam folder)

Received-SPF: pass (google.com: domain of x****@e****a.com designates 62.***.***.202 as permitted sender) client-ip=62.***.***.202;
MIME-Version: 1.0
Content-Type: multipart/alternative;     boundary="=_63e0609e24a7c5c6e72a2b53077f53c2"
Date: Tue, 28 Mar 2017 17:09:02 +0200
From: X*** **** - E*** K*** <x****@e****a.com>
To: t***@gmail.com
Subject: Fwd: Re: --- Subject of the message ---
Organization: E*** K****
In-Reply-To: <9f2d7aa8380dcf31e2a7af4795a1463d@e****a.com>
References: <CAMhvi0=PAuUOpg4eNmYn+gckaRhP6wFMMyO-frJeY5=gPC-qVg@mail.gmail.com> <9f2d7aa8380dcf31e2a7af4795a1463d@e****a.com>
Message-ID: <794731b396abba6212312e17219e6d7f@e****a.com>
User-Agent: Roundcube Webmail/1.1.5

--=_63e0609e24a7c5c6e72a2b53077f53c2
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

--- Here the content of the message ---

--=_63e0609e24a7c5c6e72a2b53077f53c2--

EDIT: Result from senderbase:

Details
IP Address  62.***.***.202
Fwd/Rev DNS Match  Help Yes

Email Reputation  Help  Neutral
Web Reputation  Help    Neutral

Last Day    Last Month
Email Volume  Help  0.0 1.9
Volume Change  Help -100%  ↓    

Hostname    sd-****.h****t.net
Domain  Help    poneytelecom.eu
Network Owner  Help Free SAS
Blacklists  Help
bl.spamcop.net  Not Listed
cbl.abuseat.org Not Listed
pbl.spamhaus.org    Not Listed
sbl.spamhaus.org    Not Listed

Your domains or IP range may be on a blacklist or lack sufficient reputation. Most of us here let someone else like AWS SES or Sendgrid handle the sending. — ceejayoz, Mar 28 '17 at 17:15
I have checked already that in all this links https://www.spamhaus.org/, https://mxtoolbox.com, https://ers.trendmicro.com/reputations, http://ipremoval.sms.symantec.com/lookup/ and all them show the server is not listed in any list. https://www.mail-tester.com/spf-dkim-check scores my mails sent as 10/10 too — spacebiker, Mar 28 '17 at 17:18
well without real info it's impossible to give real help. if you don't have consistent mailflow and good reputation (senderbase) you'll go to spam. — Jacob Evans, Mar 28 '17 at 17:23
What info do you need? This is the result from senderbase, it marks the server as neutral and not listed in any blacklist (I'll paste the result in the question for better reading) — spacebiker, Mar 28 '17 at 17:26
`Attached the headers of a blocked email sent and blocked by gmail (sent to the spam folder)` - If the email wound up in the recipients spam folder then it was in fact not blocked, nor "banned" as you state in your question. It was accepted by Gmail and then categorized as spam either by Gmail's internal spam filter or by the recipient himself/herself. Focus on the content of the message as the likely cause. Your DKIM, SPF, and DMARC are fine, as evidenced in the headers. — joeqwerty, Mar 28 '17 at 17:35
Is there any method/rules to check the content of the message? There is really nothing special in it, no attached documents at all. Just a HTML email without any suspicious link (just a mailto and a link to my website), in fact, a very normal business email, communication between two employees. — spacebiker, Mar 28 '17 at 17:42
It could be the fact this the format is HTML or it could be the hyperlinks. Try sending it without the hyperlinks and without any images/signature if they pull content from external sources. If the result is the same then try sending a plain text email as a test. — joeqwerty, Mar 28 '17 at 17:48
@joeqwerty, I think you hit the nail ! . I have tried removing all html hrefs from my email signature and now the mail got straight into the inbox . You are the man ! reply to the question and I will mark it as valid. — spacebiker, Mar 28 '17 at 18:08
I've already upvoted this question but I think you should post Edit 2 as an actual answer. On [se] sites, explicitly answering your own question is better than editing the question to incorporate an answer (a practice that might make more sense on a web forum). That way, people can upvote your answer separate to the question. — Anthony Geoghegan, Jul 07 '17 at 17:36

score 12 · Answer 1 · edited Mar 28 '17 at 19:35

12

Attached the headers of a blocked email sent and blocked by gmail (sent to the spam folder)

If the email wound up in the recipients spam folder then it was in fact not blocked, nor "banned" as you state in your question. It was accepted by Gmail and then categorized as spam either by Gmail's internal spam filter or by the recipient himself/herself. Focus on the content of the message as the likely cause. Your DKIM, SPF, and DMARC are fine, as evidenced in the headers.

Is there any method/rules to check the content of the message? There is really nothing special in it, no attached documents at all. Just a HTML email without any suspicious link (just a mailto and a link to my website), in fact, a very normal business email, communication between two employees.

It could be the fact that the format is HTML or it could be the hyperlinks. Try sending it without the hyperlinks and without any images/signature if they pull content from external sources. If the result is the same then try sending a plain text email as a test.

edited Mar 28 '17 at 19:35

Community

1

answered Mar 28 '17 at 18:10

joeqwerty

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I have to say that although this solution may helped it finally did not solve the problem. I thought it did because in Gmail, after I marked one email as "not spam", started to deliver the messages correctly. But I tried on a new account and it kept sending it to the spam folder. So I started digging and I used mxtoolbox to search for errors (dns, email, etc..). I corrected them all until there were no errors and by now hotmail.com seems to forward mails correctly. But gmail keeps marking any email as spam until the recipient previously marks the message as "not spam". – spacebiker Mar 30 '17 at 17:32
In addition I am sending everyday multiple emails to some (gmail, hotmail, yahoo, etc..) inboxes I created for the porpouse to get a better reputation, which seems to be very important for them. But I feel blind in the case of other private servers, I am not sure if the emails will arrive or not although SPF, DKIM, DMARC and all possible configuration pass the filters. I start to think that Microsoft does not like postfix and only Exchange could deliver properly to the recipients inbox.. – spacebiker Mar 30 '17 at 17:35
OK. One important thing to understand is that if the email is in the recipients Junk/Spam folder then the email was not blocked or rejected by the mail server. That is an important distinction to understand. If it's in the mailbox then the server did accept it. The email was filtered internally, not externally. – joeqwerty Mar 30 '17 at 17:38
I understand, that's why the guys from Microsoft keep telling me everything is ok with the server. But the case is that clients are not used to check the spam folder, and my customers do not like to ask theirs to check the spam for the non delivered missing message .. It's very annoying. I have been running debian servers for many years and this did not happen to me in the past.. – spacebiker Mar 30 '17 at 17:41

score 3 · Accepted Answer · answered Jul 07 '17 at 23:45

I marked the reply from joequerty as the solution but I have to say that in the end it did not solve the problem, although it helped so much.

This is how I solved it in case anyone else needs a hand. In order to know what is causing the email to be forwarded to the spam folders, you should add a DMARC record using your postmaster's address so that gmail and other mail providers will send you logs helping you to find out the clue of non-working or bad configured email servers. Once you configure the DMARC, will have to wait, probably hours until your first diagnosis emails arrive. Meanwhile, you can check your settings with mxtoolbox.com and intodns.com tools until you don't get any error. Make sure your SPF and DKIM records (of course DMARC as well) are valid. If after all this steps, your email is still marked as spam you can use the Hotmail (postmaster.live.com) and Gmail (postmaster.google.com) postmaster tools. You will probably need to get a good reputation from them before your emails are delivered to the recipients inbox as they should. Good luck !

score 0 · Answer 3 · answered Apr 16 '17 at 12:58

you need to check if earlier records from sender domain or ip were clean, if the server had sent lot of spam or has lot of email bounces then it could be in the blacklist of http://www.sorbs.net/ or smilar other sites which track and blacklist email servers

you need check your domain or ip on these sites and some servers refer this data to check blacklisting of ip's or domains

some of the sites to check are as below

https://www.dnswl.org

http://www.sorbs.net

https://www.dnswl.org/

http://ipadmin.junkemailfilter.com/remove.php

If you are clean on all above sites then your email can pass and deliver in inbox It still depends upon the receiver email settings whether your email will land in inbox or spam

Thanks for your reply but this didn't work. The IPs are not blacklisted. The problem is that due to hotmail and Google spam policies, if the IP is new and hasn't sent many emails they mark it as spam, although it is not. The real solution here is to send daily emails to addresses in those services, with insistence and patience they finally got straight into the inbox. — spacebiker, Apr 16 '17 at 20:58

Gmail and other private servers mark legitimate email as SPAM

3 Answers3

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