nanog mailing list archives

Re: Outgoing SMTP Servers


From: Carlos Martinez-Cagnazzo <carlosm3011 () gmail com>
Date: Tue, 25 Oct 2011 13:28:05 -0200

I'm curious how a traveller is supposed to get SMTP relay service
when, well, travelling. I am not really sure if I want a VPN for
sending a simple email.

And I can understand (although I am not convinced that doing so is
such a great idea) blocking 25/tcp outgoing, as most botnets will try
that method of delivery. However, I do believe that outgoing 465
SHOULD always be allowed.

regards

Carlos

On Tue, Oct 25, 2011 at 10:43 AM, Bjørn Mork <bjorn () mork no> wrote:
Owen DeLong <owen () delong com> writes:

It's both unacceptable in my opinion and common. There are even those
misguided souls that will tell you it is best practice, though general agreement,
even among them seems to be that only 25/tcp should be blocked and that
465 and 587 should not be blocked.

It is definitely considered best practice in some areas.  See e.g.
http://translate.google.com/translate?hl=en&u=http://ikt-norge.no/wp-content/uploads/2010/10/bransjenorm-SPAM.pdf
(couldn't find an english original, but the google translation looks OK)

The document is signed by all major ISPs in Norway as well as the
Norwegian research and education network operator, so it must be
considered a local "best practice" whether you like it or not.

Note that only port 25/tcp is blocked and that some of the ISPs offer a
per-subscriber optout.

Eh, this was the Northern Aurope NOG, wasn't it?




Bjørn





-- 
--
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Carlos M. Martinez-Cagnazzo
http://www.labs.lacnic.net
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