Port 25 blocked in the Koru Lounge wireless internet

Forums › New Zealand Mobile and Wireless › Port 25 blocked in the Koru Lounge wireless internet - why?

lchiu7

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#31250 10-Mar-2009 13:29

The Koru lounges offer free wireless internet for its users. I normally use Outlook HTTP to access mail and that works fine. But lately I have been wanting to access my personal mail and use Outlook, not a web service. I could never get sending mail to work - always some authentication error or some other wierd error. And to make it more confusing, if using Outlook on the same machine I connected to the Internet using my cellphone (over the VF network via Bluetooh) or for that matter, Wellington Airport's free wifi service mail would go out fine.

I am not using an ISP SMTP server but my own domain's server with authentication.

Then I had an inspiration - perhaps Koru is blocking port 25. Sure enough when I switched to the alternate port offered by my mail hosting provider, mail went out fine.

So that raises the question - what security issues could there for AirNZ to block port 25 on their free wifi service and of course not tell anybody about it?

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wellygary

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#200403 10-Mar-2009 13:58

presumably to stop spamming, or maybe they just use XTRA as their ISP

lchiu7

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#200421 10-Mar-2009 15:18

Kind of silly really. You would expect their smtp server (if indeed they had one available) to have authentication and any other SMTP server to have the same. They are just making life difficult for their (presumably higher valued) customers.

Out of interest does Xtra block port 25?

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nate

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#200463 10-Mar-2009 19:36

lchiu7: So that raises the question - what security issues could there for AirNZ to block port 25 on their free wifi service and of course not tell anybody about it?

I would say the vast majority of people who go through the Koru lounge aren't that tech savvy, possibly use VPNs to access their office email, or even webmail. It's not that uncommon to block port 25, I'd say that if it wasn't blocked people would use their connection to spam, someone may have done this in the past hence the current security policy.

Not sure about Xtra, but Xnet block outgoing connections on port 25 (excluding their own SMTP server) unless you have a static IP. Now if someone could only get China et al to implement a similar policy to help spam originating from their part of the world.

lchiu7

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#200468 10-Mar-2009 20:01

Looking at the usual crowd in the Koru I would say your assumption about their tech savviness is probably correct

As for blocking port 25 - to SPAM you still need an open SMTP server but I guess there are no shortage of them around still

I got around my problem because luckily my email hoster provides a different port for SMTP which worked fine

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davidcole

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#200478 10-Mar-2009 20:44

I just switched to xtra from telstraclear and found all my emails stop working, I am of a domain with email hosting, which uses it's own smtp server. So yes Telecom does generally block port 25.

The suggestion I had from my email provider was to use port 26. There is also a SSL smtp port 465 or something like that.

So perhaps one of those ports is available for your email as well.

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#200483 10-Mar-2009 21:15

davidcole: I just switched to xtra from telstraclear and found all my emails stop working, I am of a domain with email hosting, which uses it's own smtp server. So yes Telecom does generally block port 25.
.

You can opt out of port 25 by visiting the Xtra website. No static IP required.

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