1 Topic by sergiocesar

  • sergiocesar
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Topic: Sender Address Verification

==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.4
- Linux/BSD distribution name and version: 6.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Apache
- Manage mail accounts with iRedAdmin-Pro? yes
- Related log if you're reporting an issue:
====
Getting a lot of emails from users and server that do not respond.
NDR stacking up in the queue
how can I add or configure address verification in iRedmail so if a server do not respond we can reject or temporary refuse until we can verify the address is valid? or even if the server is real and responding.

http://www.postfix.org/ADDRESS_VERIFICATION_README.html

----

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

2 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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  • Posts: 31,088

Re: Sender Address Verification

Postfix doesn't handle this automatically. Maybe just parse the log file?

3 Reply by sergiocesar

  • sergiocesar
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Re: Sender Address Verification

ZhangHuangbin wrote:

Postfix doesn't handle this automatically. Maybe just parse the log file?

That is not what I read from the postfix manual, as it say:
from the link I posted above.
-------
What Postfix address verification can do for you

Address verification is a feature that allows the Postfix SMTP server to block a sender (MAIL FROM) or recipient (RCPT TO) address until the address has been verified to be deliverable.

The technique has obvious uses to reject junk mail with an unreplyable sender address.

The technique is also useful to block mail for undeliverable recipients, for example on a mail relay host that does not have a list of all the valid recipient addresses. This prevents undeliverable junk mail from entering the queue, so that Postfix doesn't have to waste resources trying to send MAILER-DAEMON messages back.

This feature is available in Postfix version 2.1 and later.
-----------------------------------------------

4 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: Sender Address Verification

Seems i misunderstood your post.

iRedMail has restriction rules like below in Postfix:

    reject_non_fqdn_helo_hostname
    reject_invalid_helo_hostname
    reject_unknown_sender_domain
    reject_non_fqdn_sender
    reject_unlisted_sender
    reject_unknown_recipient_domain
    reject_non_fqdn_recipient
    reject_unlisted_recipient

It helps reject some undeliverable senders/recipients. But if you want to verify each single email address, you need the Postfix tutorial in your first post.

5 Reply by sergiocesar

  • sergiocesar
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Re: Sender Address Verification

ZhangHuangbin wrote:

Seems i misunderstood your post.

iRedMail has restriction rules like below in Postfix:

    reject_non_fqdn_helo_hostname
    reject_invalid_helo_hostname
    reject_unknown_sender_domain
    reject_non_fqdn_sender
    reject_unlisted_sender
    reject_unknown_recipient_domain
    reject_non_fqdn_recipient
    reject_unlisted_recipient

It helps reject some undeliverable senders/recipients. But if you want to verify each single email address, you need the Postfix tutorial in your first post.

None of those are rejecting or preventing an NDR from trying to go back to the sender that does not respond, it not only fillup the queue but it also delay delivery as it keep trying to resend the NDR.

My question still remain:
How can I implement the address verification in iRedmail? or how else can I verify that the server sending can accept the NDR or just tell ired to DISCARD if there is a timeout or connection refused.
Is there already a configuration I can use as a model? I am surprised no one had this issue before.

6 Reply by ZhangHuangbin

  • ZhangHuangbin
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Re: Sender Address Verification

How about just follow Postfix tutorial to achieve your goal?
http://www.postfix.org/ADDRESS_VERIFICATION_README.html

7 Reply by sergiocesar

  • sergiocesar
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Re: Sender Address Verification

ZhangHuangbin wrote:

How about just follow Postfix tutorial to achieve your goal?
http://www.postfix.org/ADDRESS_VERIFICATION_README.html

I have been trying to do just that even before I posted here. I figured that with all the smart people in the forum someone have already succeed in doing so I could get some pointers.

Thanks