use smtp_bind_address or defer
in [Postfix]
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From: Sven Strickroth on 26 Sep 2009 09:12 Hi, Am 26.09.2009 15:04 schrieb Wietse Venema: >> Is it possible to tell postfix not to send mails if the >> smtp_bind_address is not available? > All reasonable TCP/IP stacks will automatically use the right source > IP address when sending out mail over the dialup link or over the > local network. I've two dial-up lines and no other internet-connection. But if the static-ip connection is down, the TCP/IP-STACK uses the other connection with a dynamic ip. With the smtp_bind_address I need to force postfix to use the static ip, instead of using the dynamic ip for sending. Using the dynamic IP has lots of disadvantages: Higher spam cores, bounces and so on. -- Best regards, Sven mailto:sven(a)clamav.net ClamAV, a GPL anti-virus toolkit http://www.clamav.net
From: Wietse Venema on 26 Sep 2009 10:18 Sven Strickroth: > Hi, > > Am 26.09.2009 15:04 schrieb Wietse Venema: > >> Is it possible to tell postfix not to send mails if the > >> smtp_bind_address is not available? > > > All reasonable TCP/IP stacks will automatically use the right source > > IP address when sending out mail over the dialup link or over the > > local network. > > I've two dial-up lines and no other internet-connection. But if the > static-ip connection is down, the TCP/IP-STACK uses the other connection > with a dynamic ip. With the smtp_bind_address I need to force postfix to > use the static ip, instead of using the dynamic ip for sending. OK, so you send out IP packets with your static IP source address out over the dynamic interface. How do the return packets from remote sites (with destination your source IP address) know that they have to travel via your dynamic interface? What routing arrangements have you made with your dynamic provider to make that work? Wietse > Using the dynamic IP has lots of disadvantages: Higher spam cores, > bounces and so on. > > -- > Best regards, > Sven mailto:sven(a)clamav.net > ClamAV, a GPL anti-virus toolkit http://www.clamav.net > > >
From: Sven Strickroth on 26 Sep 2009 11:37 Am 26.09.2009 16:18 schrieb Wietse Venema: > OK, so you send out IP packets with your static IP source address > out over the dynamic interface. no, and there's the problem. if the static-ip connection is down, postfix reports "warning: smtp_connect_addr: bind x.x.x.x: Cannot assign requested address" and then it binds to the dynamic ip and uses that. Why not add an option so that if the binding to the smtp_bind_address fails that postfix refuses to send mail. -- Best regards, Sven mailto:sven(a)clamav.net ClamAV, a GPL anti-virus toolkit http://www.clamav.net
From: Victor Duchovni on 26 Sep 2009 14:36 On Sat, Sep 26, 2009 at 05:36:30PM +0200, Sven Strickroth wrote: > Am 26.09.2009 16:18 schrieb Wietse Venema: > > OK, so you send out IP packets with your static IP source address > > out over the dynamic interface. > > no, and there's the problem. if the static-ip connection is down, > postfix reports "warning: smtp_connect_addr: bind x.x.x.x: Cannot assign > requested address" and then it binds to the dynamic ip and uses that. > > Why not add an option so that if the binding to the smtp_bind_address > fails that postfix refuses to send mail. Add filters to block outbound port 25 on the dynamic interface. Pretend your ISP has already done that for you (as many do). -- Viktor. Disclaimer: off-list followups get on-list replies or get ignored. Please do not ignore the "Reply-To" header. To unsubscribe from the postfix-users list, visit http://www.postfix.org/lists.html or click the link below: <mailto:majordomo(a)postfix.org?body=unsubscribe%20postfix-users> If my response solves your problem, the best way to thank me is to not send an "it worked, thanks" follow-up. If you must respond, please put "It worked, thanks" in the "Subject" so I can delete these quickly.
From: Stan Hoeppner on 26 Sep 2009 16:54
Victor Duchovni put forth on 9/26/2009 1:36 PM: > On Sat, Sep 26, 2009 at 05:36:30PM +0200, Sven Strickroth wrote: > >> Am 26.09.2009 16:18 schrieb Wietse Venema: >>> OK, so you send out IP packets with your static IP source address >>> out over the dynamic interface. >> no, and there's the problem. if the static-ip connection is down, >> postfix reports "warning: smtp_connect_addr: bind x.x.x.x: Cannot assign >> requested address" and then it binds to the dynamic ip and uses that. >> >> Why not add an option so that if the binding to the smtp_bind_address >> fails that postfix refuses to send mail. > > Add filters to block outbound port 25 on the dynamic interface. Pretend > your ISP has already done that for you (as many do). Or... Might it be possible, via transport_maps or something, to relay via SASL auth to your dynamic IP DSL provider's submission/outbound SMTP relay server, either on TCP 25 or 587 (whichever they support), whenever your static IP interface is down? This will definitely help to mitigate some delivery issues you mentioned WRT receivers' anti spam measures. I ran this way for almost 4 years on an SBC/AT&T PPPoE dynamic IP DSL connection with great success, although it was a single line setup. -- Stan |