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Questions tagged [greylisting]

Greylisting is a technique for fighting spam by initially rejecting emails.

Greylisting is a technique for fighting spam by initially rejecting emails, with the knowledge that valid senders will retry. Most spammers do not retry so the spam is stopped already.

Greylisting software maintains a record of delivery attempts, and when a retry arrives N minutes after an initial attempt the message is accepted.

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Postfix policyd dual usage setup - greylisting and quotas

On our server we are using policyd 1.x together with Postfix 2.1.5 for greylisting and enforcing incoming quotas from unauthorized users (ie. mail for our domains). For this, I have set up Postfix main.cf like this: smtpd_restriction_classes =…
Jens
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How long does it take for a server to get 'off greylisting'

I asked a question regarding email delays a few months ago, and I think I found a workaround. I changed our email from "noreply@site.com" to "someone@gmail.com", and it seems to work instantly again. After reading some articles, I believe this…
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Is postfix respecting greylist response?

I"m a bit confused about the activity in my mail server logs (addresses and destination redacted for privacy): Nov 1 21:00:03 mail postfix/smtp[745742]: Trusted TLS connection established to mx.example.com[192.0.2.1]:25: TLSv1.2 with cipher…
Eaten by a Grue
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Reloading sqlgrey whitelists?

I inherited admin duties of a postfix server despite having no postfix experience. It's running a service called sqlgrey that is causing all emails from google.com to be greylisted for 30 minutes. I have added *.google.com to…
snarggbargg
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Is greylisting would effect all domains that serve the same email service?

Is greylisting would effect all domains that serve the same email service? For example: Google is own @gmail.com and @googlemail.com for their email service FastMail have multi domains, you can check it from here In a nother words, Multi domains…
user2203703
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Qmail SMTP receiver always delays by 66 seconds

I am currently struggling with a problem in my qmail setup, which seems to delay my smtp receiver everytime for 66 seconds. This is for most remote hosts fine, but some seem to reach their timeout and do not deliver the mail. I am running qmail…
David
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POSTFIX: Limit outbound connections, message count, cummulative size in time window

We are sending quite large amount of email messages to our customers every month with Postfix. Big percentage of them have their email hosted with @example.com. But every month we are struggling to deliver all the messages because of…
dragularius
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Evaluation of mail server configuration

I have a mail server configured to use DNS real-time blacklists (DNSRBLs), e.g. zen.spamhaus.org, to determine whether delivered email is spam or not. I would like to evaluate my mail server's configuration since I am still receiving A LOT of…
Dimme
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How long are the default times for greylisting with postgrey?

In Wikipedia it sais: A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate the originating server will, after a delay, try again and, if sufficient…
rubo77
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Configure postfix to deliver faster when a mail got greylisted

Where do I configure the time postfix waits until it tries to resend an email from the queue if an email was grey-listed on the recipient side? I would like to configure it, so my server tries to resend the email after 2 Minutes if it was…
rubo77
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exim greylisting non-auth SMTP mail?

I have smtp auth set up on my exim4 Dqueeze server so that only auth'ed clients can use it as a mail relay. I believe this is working, e.g. thunderbird (w/out password) reports that I am "not yet authorised to send mail for X from Y". I also have…
artfulrobot
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Greylisting with two mail servers

I have two mail servers and would like to make use of greylisting, but am not sure if this simply works with two servers. E.g. when a sender gets greylisted and uses the second server for the second attempt, leading to a second greylisting, will it…
rausch
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avoid greylisting with postfix

I have an email marketing app, so we have a great volume of mails to send and sometimes a great volume to the same MX. Depending the MX configuration we enter in a greylist and the server told us (in the log) to wait some minutes or second to…
pedroaxl
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Exim log and send all mail for a given domain through another server

I administer a handful of shared web hosting servers. Recently, Yahoo has been deprioritizing/greylising all email sent from these servers. I am getting the dereaded 421 4.7.0 [TS02] Messages from my.ip.address temporarily deferred message from…
Josh
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Postfix does not retry after 451 error / greylisting

I have a forwarding server using postfix/dovecot that receives emails from a third party mail client (say gmail) and forwards the emails to the final recipient. I have noticed that when the recipient email server uses greylisting, postfix does not…
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