| Jason Costomiris on Fri, 1 Nov 2002 08:50:04 -0500 |
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On Thursday, October 31, 2002, at 06:13 PM, Jason Costomiris wrote:At my place I've got a cable modem from Comcast. My parents have Verizon DSL. When reading and sending mail from my place (using Mail.app on Mac OS X 10.2.1), everything works perfectly. However, from my parents' house, I can read fine using IMAP/SSL, but sending mail fails every time.
One assumes that you are using DHCP to obtain an IP address unique to each network, but retaining/using the same DNS name in both locations. True, though it really doesn't have anything to do with the problem at hand.. The implication here is that when you take your @comcast.com DNS name and address over to another network, (ie Verizons) mail doesn't work completely. [The Verizon relay issue makes perfect sense in that context.] Actually, I'm a firm believer that one should permit SMTP relay based on either *WHERE* you're coming from, or by authentication, NOT by what your email address is. This is why I think Verizon's mail relays are broken - a different issue, but true nonetheless... I assume that your RedHat mail server is NOT configured as a peer on the Internet, but rather one that feeds all outgoing mail back up to a Comcast mail server for distribution. [Last I checked, Comcast still prohibits you from running any kind of server on your "Comcast@home" setup. If you want to run any kind of server, you need to upgrade to "Comcast@work"... and send them more money.] This is where your assumption kind of falls apart. :) The server is in a colo, not on comcast, not on verizon. Since I didn't say it was on Comcast or Verizon's network, I thought this was simply a given. Apparently nobody else seems to think it's perfectly reasonable to have a server connected to the Internet. :) This is coming to you from an iMac via Bell Atlantic DSL (yes, it's that old.) However, I do use DCAnet as an ISP, so its not exactly Verizon DSL -- I have static IPs. I run a local mail server under my own registered domain. [My mail server happens to be an Alpha running Tru64.] That's the key difference here.. All you're getting from Verizon is layer 2 connectivity. DCA has a connection into the BA SMDS/ATM cloud, and that's how your packets make it from your local CO's DSLAM to DCA's network.. I would expect your configuration to work locally on Comcast since that is what it is configured for. However, I would guess that if you had a Verizon configured setup, you would encounter the same problems. I would guess that if you configured your PowerBook to use the Comcast mail server and used it on Verizon's network, that it would work. Sure, I agree with you there, but we're talking about hitting a mail server that's in a colo. Since my mail server decides on whether or not to relay based on SASL logins, I think it's perfectly reasonable to expect it to work properly when I'm on Comcast *OR* on Verizon. My experience with Consumer Cable modem setups (ie @home) in general has been that they are far more restrictive than ISP based DSL. "Always on" does not make you a Peer on the Internet. Commercial Cable modem setups (@work) on the other had are (or can be) a different story. Also, Comcast service has always been far more restrictive than Time Warner's RoadRunner service in Philadelphia. Interesting.. My experience is quite the opposite. My downloads are MUCH faster than anyone I know that's got DSL, and I've never had a bit of trouble with what Comcast does and does not let me do.. --
Jason Costomiris <><
E: jcostom {at} jasons {dot} org / W: http://www.jasons.org/
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