: Random behavior sending mails to Gmail I am sick to warn website users (new and existing) who have Gmail accounts "Check your spam folder". I suffer this as a webmaster and as a user. For

I am sick to warn website users (new and existing) who have Gmail accounts "Check your spam folder". I suffer this as a webmaster and as a user.

For one website: The Port25 Solutions, Inc. team

Summary of Results

SPF check: pass
DomainKeys check: neutral
DKIM check: pass
Sender-ID check: pass
SpamAssassin check: ham

SpamAssassin check details:

SpamAssassin v3.3.1 (2010-03-16)

Result: ham (-2.0 points, 5.0 required)

pts - rule - name - description

-1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%
[score: 0.0000]
0.0 HTML_MESSAGE BODY: HTML included in message
-0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's
domain
0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid
-0.1 DKIM_VALID Message has at least one valid DKIM or DK signature

Example 1) I have a website with fail2ban intalled. It sends a report to smth@gmail.com each time a firewall rule is broken.
Plain text the messages only differs on offender's IP and some related data. Most of these mails go to Inbox but I found some gmail spam folder.

Example 2) A Gmail user had registered in my system. He got the confirmation mail and following ones (purchases, whatever) but one day he recives a notice in his spam folder.

I know that if the user answers just one of any of the emails he recives then Gmail "understands" my server is dependable and Gmail does not deliver my messages to spam folder. Maybe I should ask "Please answer this email to confirm registration"
to accomplish that. But the problem is if this first mail is considered as spam.

I've read a lot of advices about this issue and implemented lot of things.
For some sites I had implemented MX in Google mail servers but it is not free anymore and people don't want to pay hundreds dollars on it.

What do you suggest?

This is the body of Example 2 banned email (subject:[Fail2Ban] SSH: banned 42.96.162.225) headers are always the same

Hi,

The IP 42.96.162.225 has just been banned by Fail2Ban after
5 attempts against SSH.

Here are more information about 42.96.162.225:

[Querying whois.arin.net]
[Redirected to whois.apnic.net]
[Querying whois.apnic.net]
[whois.apnic.net]
% [whois.apnic.net node-3]
% Whois data copyright terms www.apnic.net/db/dbcopyright.html
inetnum: 42.96.128.0 - 42.96.255.255
netname: ALIBABA-BJ-NET
descr: Alibaba (Beijing) Technology Co., Ltd.
descr: 9F,Tower A Winterless center,NO.1 West Da Wang Lu,
descr: Chaoyang District,Beijing
country: CN
admin-c: PW270-AP
tech-c: PW270-AP
status: ALLOCATED PORTABLE
mnt-by: MAINT-CNNIC-AP
mnt-lower: MAINT-CNNIC-AP
mnt-irt: IRT-CNNIC-CN
changed: hm-changed@apnic.net 20110311
source: APNIC

person: Peter Wang
nic-hdl: PW270-AP
e-mail: huijun.wanghj@alibaba-inc.com
address: No.99 HuaXing Rd. Hangzhou,310099
phone: +86-571-85022088
phone: +86-010-65985220
fax-no: +86-010-65985401
country: CN
changed: ipas@cnnic.net.cn 20080115
mnt-by: MAINT-CNNIC-AP
source: APNIC

Regards,

Fail2Ban

Of course the message varies according to whois IP