RFC 1123 (http://www.ietf.org/rfc/rfc1123.txt)
5.3.1.1 Sending Strategy
The general model of a sender-SMTP is one or more processes
that periodically attempt to transmit outgoing mail. In a
typical system, the program that composes a message has some
method for requesting immediate attention for a new piece of
outgoing mail, while mail that cannot be transmitted
immediately MUST be queued and periodically retried by the
sender. A mail queue entry will include not only the
message itself but also the envelope information.
The sender MUST delay retrying a particular destination
after one attempt has failed. In general, the retry
interval SHOULD be at least 30 minutes; however, more
sophisticated and variable strategies will be beneficial
when the sender-SMTP can determine the reason for non-
delivery.
Retries continue until the message is transmitted or the
sender gives up; the give-up time generally needs to be at
least 4-5 days. The parameters to the retry algorithm MUST
be configurable.
Cheers,
Phil
--
Phil Randal
Network Engineer
Herefordshire Council
Hereford, UK
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Sent: 23 November 2006 06:57
> To: [email protected]
> Subject: Re: Greylisting
>
> Philip Prindeville wrote:
> > Don't they? I thought the recommended retry time was 2 minutes,
> > doubling on each failure, and maxing out at 2 hours.
>
> The traditional Sendmail would retry either every 15 or every 30
> minutes. This would almost always be seen as the command line setting
> as sendmail -q30m. But this may have changed in recent Sendmail
> releases. I just checked a stock RHEL4 system and the queue retry
> time by default there is 1h. So from such a system a greylisting
> would delay the initial message by 1h. Subsequent messages would pass
> without delay.
>
> Bob
>
