1 Topic by Ascar (edited by Ascar 2017-08-30 20:07:37)

  • Ascar
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Topic: Fresh install, can send email, can't receive - SMTP error 550

======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.7
- Linux/BSD distribution name and version: Ubuntu 16.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? Not yet
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello, Zhang.  Please help me with an advice.

I made a fresh installation of iRedMail and I am able to send messages outside my domain.  I can't receive messages though.  When I send a message to iRedMail server by replying to the message received I get the message bounce with the error

"The response was:

550 Address unknown

Final-Recipient: rfc822; aomarov@supermicrodirect.net
Action: failed
Status: 5.0.0
Remote-MTA: dns; ums1.kulverstukas.com. (213.136.64.233, the server for the
domain supermicrodirect.net.)
Diagnostic-Code: smtp; 550 Address unknown
Last-Attempt-Date: Wed, 30 Aug 2017 03:39:45 -0700 (PDT)"

All DNS entries seem to be properly set up as I see on the firewall that the message arrived and was forwarded to the mail server, however the message was rejected because it does not know the recipient's email address.

----

Spider Email Archiver: On-Premises, lightweight email archiving software developed by iRedMail team. Supports Amazon S3 compatible storage and custom branding.

2 Reply by schnappi

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Re: Fresh install, can send email, can't receive - SMTP error 550

Look at the log file /var/log/mail.log and post the entries relevant to the email being rejected.

3 Reply by Ascar

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Re: Fresh install, can send email, can't receive - SMTP error 550

Hi, schnappi

This is what I was able to fish out from the log file:

Aug 31 10:56:22 UMS1 postfix/postscreen[1753]: CONNECT from [192.168.2.254]:47628 to [192.168.2.104]:25
Aug 31 10:56:22 UMS1 postfix/postscreen[1753]: PASS OLD [192.168.2.254]:47628
Aug 31 10:56:22 UMS1 postfix/smtpd[1756]: connect from unknown[192.168.2.254]
Aug 31 10:56:23 UMS1 postfix/smtpd[1756]: NOQUEUE: reject: RCPT from unknown[192.168.2.254]: 451 4.7.1 <aomarov@supermicrodirect.net>: Recipient address rejected: Intentional policy rejection, please try again later; from=<> to=<aomarov@supermicrodirect.net> proto=ESMTP helo=<fw.coretech-me.com>
Aug 31 10:56:23 UMS1 postfix/smtpd[1756]: disconnect from unknown[192.168.2.254] ehlo=1 mail=1 rcpt=0/1 quit=1 commands=3/4

Please share with me how to handle this.

Thanks in advance

4 Reply by Ascar

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Re: Fresh install, can send email, can't receive - SMTP error 550

OK, I did some googling and found information on your site suggesting that the messages are rejected due to greylisting being on.  Disabled, restarted the iredadp service and mail flows now properly in and out.

I will have to find out more about greylisting and whether it is worth keeping it on the server.
So far it looks to me as a crazy, oversuspicious cop who want see a criminal in every person.

5 Reply by RikuS

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Re: Fresh install, can send email, can't receive - SMTP error 550

Ascar wrote:

I will have to find out more about greylisting and whether it is worth keeping it on the server.

Definitely worth keeping it, at the end of the day Greylisting spots lots of spam. But you can easily disable it per domain or user and also whitelist some senders/servers.

6 Reply by schnappi (edited by schnappi 2017-09-06 05:19:31)

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Re: Fresh install, can send email, can't receive - SMTP error 550

Always disable greylisting (http://www.iredmail.org/docs/manage.ire … reylisting). Would recommend same. iRedMail sends the vast majority of spam email to the spam folder. Also nothing is stopping a spam relay from retrying a failed send (although agree this usually doesn't happen).

Just seems like greylisting causes more delays to emails that want to get than anything else.