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Topic: SMTP rejection 450

- iRedMail version (check /etc/iredmail-release): 0.9.8
- Linux/BSD distribution name and version: Cent OS 7.4
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx):Nginx
- Manage mail accounts with iRedAdmin-Pro? yes, 2.9.0
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Our mail server is rejecting mails from trusted domains like vodafone.com due to 450 EHLO rejetc.

Log from /var/log/maillog

Jul 31 13:53:27 mailserver postfix/smtpd[25368]: NOQUEUE: reject: RCPT from mr15.vodafone.in[122.15.128.18]: 450 4.7.1 <INMUM01SBG7.vodafone.com>: Helo command rejected: Host not found; from=<Mohammad.Mohiuddin@vodafone.com> to=<avinash.srivastava@medhaj.com> proto=ESMTP helo=<INMUM01SBG7.vodafone.com>

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Re: SMTP rejection 450

saquib.akhtar wrote:

Helo command rejected: Host not found; ... helo=<INMUM01SBG7.vodafone.com>

You can whitelist its HELO hostname in /etc/postfix/helo_access.pcre, like this:

/\.vodafone\.com$/ OK

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Re: SMTP rejection 450

Now the error is coming due to  Recipient address rejected: Intentional policy rejection

Thanks for replying so quickly!

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Re: SMTP rejection 450

How to decrease the greylisting default time of 15 minutes ?

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Re: SMTP rejection 450

Add setting in /opt/iredapd/settings.py and restart iredapd service:

GREYLISTING_BLOCK_EXPIRE = 15

15 means 15 minutes, you can decrease or increase it.

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Re: SMTP rejection 450

ZhangHuangbin wrote:

Add setting in /opt/iredapd/settings.py and restart iredapd service:

GREYLISTING_BLOCK_EXPIRE = 15

15 means 15 minutes, you can decrease or increase it.

Thanks I found it yesterday and it worked!!!

Just wanted to know that turning greylisting to learning mode will effect security of spamming also ?

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Re: SMTP rejection 450

saquib.akhtar wrote:

Just wanted to know that turning greylisting to learning mode will effect security of spamming also ?

Training mode will not reject messages, it just update sql db for future use.

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Re: SMTP rejection 450

ZhangHuangbin wrote:
saquib.akhtar wrote:

Just wanted to know that turning greylisting to learning mode will effect security of spamming also ?

Training mode will not reject messages, it just update sql db for future use.

Does it has to do with spamming policy and quarantine ?

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Re: SMTP rejection 450

saquib.akhtar wrote:

Does it has to do with spamming policy and quarantine ?

not relevant.

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Re: SMTP rejection 450

ZhangHuangbin wrote:
saquib.akhtar wrote:

Does it has to do with spamming policy and quarantine ?

not relevant.

Thanks for the support !!