1 Topic by lug

  • lug
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Topic: Mails from facebook blocked because misdetection of dynamic ip address

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.9
- Deployed with iRedMail Easy or the downloadable installer? installer
- Linux/BSD distribution name and version: ubuntu 16.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): mysql
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hi,

currently mails from facebook are blocked, because iredmail falsely detect them as dynamic ip address...

Nov  5 17:29:41 mail postfix/smtpd[30096]: NOQUEUE: reject: RCPT from 66-220-155-155.mail-mail.facebook.com[66.220.155.155]: 554 5.7.1 <66-220-155-155.mail-mail.facebook.com>: Helo command rejected: ACCESS DENIED. Your email was rejected because the sending mail server appears to be on a dynamic IP address that should not be doing direct mail delivery (66-220-155-155); from=<security@facebookmail.com> to=<xxx@yyy.zzz> proto=ESMTP helo=<66-220-155-155.mail-mail.facebook.com>

----

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2 Reply by lug (edited by lug 2019-11-06 18:31:33)

  • lug
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Re: Mails from facebook blocked because misdetection of dynamic ip address

Also:

66.220.155.145
66.220.155.138
69.171.232.131

3 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: Mails from facebook blocked because misdetection of dynamic ip address

PREPEND one line in /etc/postfix/helo_access.pcre should fix this:

/^\d{1,3}-\d{1,3}-\d{1,3}-\d{1,3}\.mail-mail\.facebook\.com$/ DUNNO

4 Reply by lug

  • lug
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Re: Mails from facebook blocked because misdetection of dynamic ip address

Which database does iredmail use to determine if it's static or dynamic?
I just noticed this affects many different facebook IPs

ZhangHuangbin wrote:

PREPEND one line in /etc/postfix/helo_access.pcre should fix this:

/^\d{1,3}-\d{1,3}-\d{1,3}-\d{1,3}\.mail-mail\.facebook\.com$/ DUNNO

would fix it for me, but I guess this could affect many other users.
I also looked at other iredmail installations from customers I supervise, same error.

5 Reply by ZhangHuangbin

  • ZhangHuangbin
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Re: Mails from facebook blocked because misdetection of dynamic ip address

lug wrote:

Which database does iredmail use to determine if it's static or dynamic?

For HELO checks, in /etc/postfix/helo_access.pcre.

6 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: Mails from facebook blocked because misdetection of dynamic ip address

lug wrote:

would fix it for me, but I guess this could affect many other users.
I also looked at other iredmail installations from customers I supervise, same error.

We will mention this fix in iRedMail upgrade tutorial:
https://docs.iredmail.org/upgrade.iredm … ok-servers

For users deployed with iRedMail Easy platform, this fix is included in the latest release (2019102201). If you didn't upgrade yet, please login to iRedMail Easy platform and upgrade.
https://easy.iredmail.org/