On Mon, 2005-07-11 at 20:47 +0100, Mark Pasola wrote:
> Yes. I suddenly can't send SMTP mail to mail.btinternet.com at work
> using Thunderbird. The change occured last week.
Many large networks (Freeserve for instance) block port 25 the SMTP
port, while providing an SMTP server within the network.
Polite ones do it transparently, so you plug your laptop into the
network in Smallco, and it thinks it is sending mail via bigco.com
whereas it is actually sending it via smallco.co.uk 's server.
Impolite ones just reject it and your mail doesn't work until you tell
Postfix or Thunderbird or whatever to use post.smallco.co.uk
and then swap back to post.bigco.com when you get back to Bigco .
One configuration choice I'm less convinced about the merit of is that
all the organisational SMTP servers seem to be configured to only accept
mail from the relay.nhs.uk and presumably smtp1.nhs.net machines.
This means that I can't just send a message direct from my machine
through nothing but routers (which tend to be short on storage) to eg
our local hospital, instead it has to all go through a choke point.
So far the choke point has been v v reliable, but ...
> I can still send via BT Internet/Yahoo's webmail service.
Port 80 traffic I guess.
--
Adrian Midgley <[log in to unmask]>
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