From owner-freebsd-questions@FreeBSD.ORG Tue Mar 30 09:14:09 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 68B3C1065678 for ; Tue, 30 Mar 2010 09:14:09 +0000 (UTC) (envelope-from j.mckeown@ru.ac.za) Received: from a.mail.ru.ac.za (a.mail.ru.ac.za [IPv6:2001:4200:1010::25:1]) by mx1.freebsd.org (Postfix) with ESMTP id 7703E8FC08 for ; Tue, 30 Mar 2010 09:14:08 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=ru-msa; d=ru.ac.za; h=Received:From:Organization:To:Subject:Date:User-Agent:References:In-Reply-To:X-Face:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id:X-Virus-Scanned:X-Authenticated-User; b=XNyViCbNHKGEHK5a6eL208QYMY2SP1Jsh5MtNsUyIHg2fQ8qacimI+zuaKKVs6UFsBHYg0PRufqjOg9knAZTf5MSg2yndhZqLt0zpaFj5GnvUz8RSDuEhojMFkYvayqp; Received: from vorkosigan.ru.ac.za ([2001:4200:1010:1058:219:d1ff:fe9f:a932]:63788) by a.mail.ru.ac.za with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1NwXWP-00099j-GV for freebsd-questions@freebsd.org; Tue, 30 Mar 2010 11:14:05 +0200 From: Jonathan McKeown Organization: Rhodes University To: freebsd-questions@freebsd.org Date: Tue, 30 Mar 2010 11:14:05 +0200 User-Agent: KMail/1.9.10 References: <4BAED536.2060205@rzweb.com> <4BB1A8B4.6080506@infracaninophile.co.uk> In-Reply-To: <4BB1A8B4.6080506@infracaninophile.co.uk> X-Face: $@VrUx^RHy/}yu]jKf/<4T%/d|F+$j-Ol2"2J$q+%OK1]&/G_S9(=?utf-8?q?HkaQ*=60!=3FYOK=3FY!=27M=60C=0A=09aP=5C9nVPF8Q=7DCilHH8l=3B=7E!4?= =?utf-8?q?2HK6=273lg4J=7Daz?=@1Dqqh:J]M^"YPn*2IWrZON$1+G?oX3@ =?utf-8?q?k=230=0A=0954XDRg=3DYn=5FF-etwot4U=24b?=dTS{i X-Virus-Scanned: a.mail.ru.ac.za (2001:4200:1010::25:1) X-Authenticated-User: s0900137 from vorkosigan.ru.ac.za (2001:4200:1010:1058:219:d1ff:fe9f:a932) using auth_plaintext Subject: Re: Freebsd, postfix and push email X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Mar 2010 09:14:09 -0000 On Tuesday 30 March 2010 09:31:00 Matthew Seaman wrote: > On 30/03/2010 03:01:27, Tim Judd wrote: > > I've never heard of either, but when I configure my IMAP server and > > put any mail client to it, as soon as a mail is delivered, the mail > > client is notified. > > That's the IDLE extension to IMAPv4 -- it's not a push protocol as > such: the client still has to log into the server rather than vice > versa, but once the client has read all the available e-mail, it can > put itself into an idle state, and the server will wake it up as soon > as any new e-mail comes in. Yes. In fact, one of the nice things about IMAPrev4 as a protocol is that the server is allowed (in fact, required by rfc3501) to notify the client if the mailbox size increases while executing any command, by sending an EXISTS response which the client is required to handle. IDLE is just a command that takes a long time to execute (specifically, until the client ends it or the server's time limit is reached) so that the server has to send EXISTS responses whenever mail comes in. Jonathan