1 Topic by jaryd

  • jaryd
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Topic: Multiple Mail Domains + Single Server

Hey Guys,
Just installed a fresh CentOS 5.4 server running 2.6.32.13-grsec-89 and iRedMail. I've got it set up properly for my first domain, and now I'd like to add a second. I have created the proper MX records, and have used PostFixAdmin to add my second domain but mail delivery is taking a very long time. In my logs I am receiving "NOQUEUE: reject: RCPT from unknown" for this particular domain.

After some googling I discovered that this error indicates postfix doesn't believe it is supposed to be the final destination for that particular message, and attempts to figure out where to forward it. Wondering if I need to modify any additional settings in order to make my second domain work okay on the same server as my first (primary) mail domain.
Thanks for your time,
Jaryd

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

2 Reply by shake

  • shake
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Re: Multiple Mail Domains + Single Server

you can try sent email again and would find receive email quickly.

this is greylisting feature.

Greylisting

Typically, a server that utilizes Greylisting will record the following three pieces of information (referred to as triplet) for all incoming e-mail.

    * The IP address of the connecting host
    * The envelope sender address
    * The envelope recipient address

The client is checked against the mail server's internal whitelists (if any) first. Then, if the triplet has never been seen before, it is greylisted for a period of time (how much time is dependent on the server configuration). The e-mail is rejected with a temporary error. The assumption is that since temporary failures are built into the RFC specifications for e-mail delivery, a legitimate server will attempt to connect again later on to deliver the e-mail.



Greylisting is effective because many mass e-mail tools utilized by spammers are not set up to handle temporary failures (or any failures for that matter) so the Spam is never received.



This feature can reduce e-mail traffic up to 50%. Greylisted e-mails never reach your mail server and your mail server will stop sending useless "Non Delivery Reports" to spammers.

3 Reply by jaryd

  • jaryd
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Re: Multiple Mail Domains + Single Server

Shake,
Thanks so much for the informative reply. In fact you are absolutely right! Greylisting is the culprit (if you can call it that since it's actually working to specifcation) in this scenario, and so when I turned it off I began receiving mail with very little latency.

Do you suppose there are going to be very significant downsides for turning off greylisting?
Thanks again,
Jaryd

4 Reply by shake

  • shake
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Re: Multiple Mail Domains + Single Server

/etc/postfix-policyd.conf

#   1=on  0=off
GREYLISTING=0

5 Reply by jaryd

  • jaryd
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Re: Multiple Mail Domains + Single Server

Oh heh yeah I did that. What do you think though... am i setting myself up for spam galore?