On 24-Apr-08, at 4:29 PM, Matt wrote:
> Steve Hume wrote:
>> Your rules have an SPF record like this
>> "v=spf1 mx ptr ip4:24.207.1.0/24 ?all"
>
> You're assuming I'm writing to the list from my place
of work ;)
Shouldn't matter.
Most networks will let port 465 SSL SMTP pass out the
firewall. That
way you can send using your SMTP from anywhere but foreign
webmail
portals. That's how I do it. Since I use IMAP I have to log
into my
server anyways to keep the sent mail folder updated. The
only case I
could not stop was my Blackberry. It sends from BB SMTP
servers. I had
to add them to my SPF record so I could keep the -all. You
can also
add the SMTP servers that you do use while "not at
work" to the SPF
record. It took me a year before I went -all, but after
having it set
that way for more than a year, I see no ill effects. No
backscatter
towards my server either; but that might be Surgemail
dealing with it?
Yes the SPF system needs cooperation for it to be an
effective anti-
spam tool.
My personal feeling on the C/R tool is that it is deflecting
60% spam
and 37% Unsolicited HTML marketing emails to servers that
don't have
SPF setup, and 3% emails from new sources that really should
have SPF
too. The marketing guys should know better and setup SPF.
The bad use
of innocent sender addresses for spam has the baby step of
setting up
strict SPF for your domains so that other servers can at
least know
not to backscatter.
Since my little server deals with spam that is greater than
50% of all
email transactions, the internet must still be largely spam.
I am
grateful to Netwin for the tools they have provided.
My favorite application of Friends C/R is when one of my
users gets a
request from a "spammer" on orkut.com. Of course
they get a Friend
challenge Then,
they don't seem to want to be a Friend all of a
sudden and don't confirm. These orkut messages are in the
grey zone,
as they are usually spam nut could be a real new friend
attempt also.
I think the Friend challenge is quite good in this
scenario.
Go "-all", you have the right tool for the job.
Steve Hume
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