[Dovecot] what best for anti-spam filter?

[Noel Butler]

On Tue, 2012-07-24 at 07:22 -0500, Stan Hoeppner wrote:

> On 7/24/2012 7:13 AM, Morten Stevens wrote:
> 
> > Jul 24 12:27:32 mx1 sendmail[31933]: q6OARUOM031928:
> > to=<dovecot at dovecot.org>, delay=00:00:02, xdelay=00:00:01, mailer=esmtp,
> > pri=152317, relay=dovecot.org. [193.210.130.67], dsn=2.0.0, stat=Sent
> > (Ok: queued as 35AF81AE8359)
> > Jul 24 12:28:32 mx1 sendmail[31933]: q6OARUOM031928:
> > to=<manu at netbsd.org>, delay=00:01:02, xdelay=00:01:00, mailer=esmtp,
> > pri=152317, relay=mail.netbsd.org. [149.20.53.66], dsn=4.0.0,
> > stat=Deferred: Connection timed out with mail.netbsd.org.
> > Jul 24 12:42:57 mx1 sendmail[32292]: q6OARUOM031928:
> > to=<manu at netbsd.org>, delay=00:15:27, xdelay=00:01:00, mailer=esmtp,
> > pri=242317, relay=mail.netbsd.org. [149.20.53.66], dsn=4.0.0,
> > stat=Deferred: Connection timed out with mail.netbsd.org.
> > Jul 24 12:50:53 mx1 sendmail[32518]: q6OARUOM031928:
> > to=<manu at netbsd.org>, delay=00:23:23, xdelay=00:00:02, mailer=esmtp,
> > pri=332317, relay=mail.netbsd.org. [149.20.53.66], dsn=4.7.1,
> > stat=Deferred: 450 4.7.1 <manu at netbsd.org>: Recipient address rejected:
> > Greylisting in action, please try later
> > Jul 24 12:58:41 mx1 sendmail[312]: q6OARUOM031928: to=<manu at netbsd.org>,
> > delay=00:31:11, xdelay=00:00:02, mailer=esmtp, pri=422317,
> > relay=mail.netbsd.org. [149.20.53.66], dsn=4.7.1, stat=Deferred: 450
> > 4.7.1 <manu at netbsd.org>: Recipient address rejected: Greylisting in
> > action, please try later
> > Jul 24 13:42:21 mx1 sendmail[1461]: q6OARUOM031928:
> > to=<manu at netbsd.org>, delay=01:14:51, xdelay=00:00:01, mailer=esmtp,
> > pri=512317, relay=mail.netbsd.org. [149.20.53.66], dsn=4.7.1,
> > stat=Deferred: 450 4.7.1 <manu at netbsd.org>: Recipient address rejected:
> > Greylisting in action, please try later
> > Jul 24 13:50:53 mx1 sendmail[1672]: q6OARUOM031928:
> > to=<manu at netbsd.org>, delay=01:23:23, xdelay=00:00:02, mailer=esmtp,
> > pri=602317, relay=mail.netbsd.org. [149.20.53.66], dsn=4.7.1,
> > stat=Deferred: 450 4.7.1 <manu at netbsd.org>: Recipient address rejected:
> > Greylisting in action, please try later
> > 
> > This is exactly the reason why greylisting is bad.
> 
> I have yet to hear of a bot that retries.  Thus, there's not reason to


they exist


> set a wait period more than a few seconds, causing the situation above.
> 


Not surprising Stanley still doesn't get it,  how many  mail servers
have a retry under 10 minutes anyway, sure as hell none at a "few
seconds" , and busy servers with queue limits, could mean a msg set to
be retried in 10 mins, may still yet take 2 hours to find its spot in a
queue (yes, seen it)

Sendmails greet pause as was noted by an earlier poster was not a bad
method, but like grey listing, some spam bots adjusted to suit.

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