can't send mail on other wifi networks

[_adrian]

So I can send from Outlook 2003 on my home wifi network, or any of the
neighboring networks around my home. I travel down to California, and NO
wifi networks allow Outlook to communicate with my mail servers. If I
connect via ethernet, then everything works fine. The problem is only with
unknown wifi routers... and its not a port 25 problem ...

Thoughts?

 

[Brian Tillman]

So I can send from Outlook 2003 on my home wifi network, or any of the
neighboring networks around my home. I travel down to California, and
NO wifi networks allow Outlook to communicate with my mail servers. If I
connect via ethernet, then everything works fine. The problem is
only with unknown wifi routers... and its not a port 25 problem ...

You have to use the SMTP server supplied by the network to which you are
attached or that network will consider you to be relaying.

 

[Vanguard]

So I can send from Outlook 2003 on my home wifi network, or any of the
neighboring networks around my home.

Until your neighbors realize that someone (you) is stealing their
bandwidth and then secure their wireless hubs and routers so you can't
use them anymore.

I travel down to California, and NO wifi networks allow Outlook to
communicate with my mail servers.

WHICH mail servers? POP3, IMAP, SMTP, Exchange, other? Apparently
California folks (wherever you are visiting) are smart enough to
lockdown their wifi network. Guess you'll have to find those freebie
wifi hotspots to do your war driving.

If I connect via ethernet,

So now you are talking about a wired network? WHERE is that wired
network? Guess that wired network does not require you to use their own
SMTP server when sending e-mail from their domain, but many do. Since
you don't know what are these wifi networks that you are stealing
bandwidth then you don't know what their ISPs require (and it looks like
their ISPs require authentication to the ISP's SMTP server to send
outbound e-mails).

 

[_adrian]

Well, I hardly consider it stealing if its a service that they're providing
in their coffee houses. But all the same, I just find it hard to believe
that ALL of them have JUST SMTP locked down.

 

[Brian Tillman]

Well, I hardly consider it stealing if its a service that they're
providing in their coffee houses. But all the same, I just find it
hard to believe that ALL of them have JUST SMTP locked down.

However difficult to believe it may be, it's common. ISPs don't allow
anyone but ISP account holders to use their SMTP servers and if you're on
their net, they expect you to use their SMTP server.

 

[Vanguard]

Well, I hardly consider it stealing if its a service that they're
providing in their coffee houses.

And that is why I mentioned the wifi hotspots which are setup for the
type of connection you are getting (but remember that you have no
security since anyone else on that same wifi hotspot can look at your
traffic).

"I can send ... neighboring networks around my home." Oh, your house is
surrounded by Internet cafes using wifi? Didn't think so. You are
stealing bandwidth from your neighbors unless they have given you
permission but then they should still be locking down their wifi
networks and then just letting your host connect to them (i.e., you just
become another one of their internal nodes).

But all the same, I just find it hard to believe that ALL of them have
JUST SMTP locked down.

Well, you understand how and why an ISP locks down a user on their
network to force them to use the SMTP server on their network (to
eliminate spam abuse). Okay, the flip side of that anti-spam mechanism
is that the receiving domain wants you to authenticate to their SMTP
server to prove you actually have permission to use their resources.
You are coming from a different domain and yet you think your "home"
domain somehow magically knows you are who you claim to be and should
automatically open your account for access? That would ANYONE could use
your account. You probably have to authenticate to your own e-mail
provider's SMTP server. Go into the e-mail account and configure it to
authenticate to your e-mail provider's SMTP server.

ISPs may block outbound SMTP traffic that does *not* use that ISP's SMTP
server (i.e., you are not allowed to send mail using an off-domain mail
host). However, ISPs may also block inbound traffic that originates
from off their domain unless the user authenticates they have permission
to use that e-mail provider's resources. The block can be outbound,
inbound, or both.

Off-domain port 25 (SMTP) traffic blocked to thwart spam from spamming
or infected customers:

http://www.commercestreet.com/Blocking_Port_25.htm
http://help.yahoo.com/help/us/mail/pop/pop-38.html

http://www.postcastserver.com/help/Port_25_Blocking.aspx
http://www.aota.net/Troubleshooting/port25.php4
http://www.spamhaus.org/faq/answers.lasso?section=ISP Spam Issues#133
http://www.findarticles.com/p/articles/mi_zdewk/is_200406/ai_ziff129473

http://www.google.com/search?q=+block++"port+25"++SMTP++spam