JF Mezei

When sending email to a friend from my iphone, it would end up as spam
in his mailbox.

He sent me back some headers:

X-Spam-Status: Yes, score=2.6 required=2.0 tests=MIME_QP_LONG_LINE,RDNS_NONE
autolearn=disabled version=3.2.5
X-Spam-Report:
* 2.5 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars
* 0.1 RDNS_NONE Delivered to trusted network by a host with no rDNS


The second one is likely because the IP address given by the mobile
network to the iPhone doesn't have reverse DNS.


But the first one was surprising. Turns out that the iPhone does split
lines at 76 characters, but then adds the = sign which makes the lines
longer than 76, so the spam assasing raises the spam likelyhood above
the limit.

DevilsPGD

In message <4f0d2365$0$8833$c3e8da3$12bcf670@news.astraweb.co m> someone
claiming to be JF Mezei <jfmezei.spamnot@vaxination.ca> typed:

>When sending email to a friend from my iphone, it would end up as spam
>in his mailbox.
>
>He sent me back some headers:
>
>X-Spam-Status: Yes, score=2.6 required=2.0 tests=MIME_QP_LONG_LINE,RDNS_NONE
> autolearn=disabled version=3.2.5
>X-Spam-Report:
> * 2.5 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars
> * 0.1 RDNS_NONE Delivered to trusted network by a host with no rDNS
>
>
>The second one is likely because the IP address given by the mobile
>network to the iPhone doesn't have reverse DNS.
>
>
>But the first one was surprising. Turns out that the iPhone does split
>lines at 76 characters, but then adds the = sign which makes the lines
>longer than 76, so the spam assasing raises the spam likelyhood above
>the limit.

There's a handful of problems here, but they all come down to PEBCAK on
the part of the mail server administrator's part.

| X-Spam-Status: Yes, score=2.6 required=2.0

Well there's your first problem: Required=2.0 is insane, and will cause
such a high false positive rate that he may as well not bother checking
his Inbox and just use the Spam folder as his primary Inbox.

SpamAssassin rules are balanced for a target score of 5.5, adjusting
significantly away from this will significantly affect results
negatively.

| version=3.2.5

This version of SpamAssassin is ancient, and depreciated. Upgrade it, or
don't complain when scanning results are crap.

| * 2.5 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars

Regarding the rule itself, check
http://wiki.apache.org/spamassassin/...E_QP_LONG_LINE for details.
Check your line lengths to see if they're 78 rather than 76 characters,
if so, then this is normal and expected behaviour. Running a
non-depreciated version of SpamAssassin might have solved this without
your friend embarrassing himself by exposing his poor configuration.

Even if the iPhone mail client is spitting out malformed mail (it
wouldn't shock me, it's got a number of other significant issues), a
score of 2.6 simply isn't spam.

--
It's always darkest before dawn. So if you're going to
steal your neighbor's newspaper, that's the time to do it.

JF Mezei

DevilsPGD wrote:

> Well there's your first problem: Required=2.0 is insane, and will cause
> such a high false positive rate that he may as well not bother checking
> his Inbox and just use the Spam folder as his primary Inbox.

Interesting. Yet, this terrible setting did cause me to realise that the
MAIL.APP on the iPhone sends out 77 character lines. (when you include
the = sign)

> This version of SpamAssassin is ancient, and depreciated. Upgrade it, or
> don't complain when scanning results are crap.

Since the offending SMTP server belons to a large australian ISP, I am
not really in a position to tell them what to do :-)

> Regarding the rule itself, check
> http://wiki.apache.org/spamassassin/...E_QP_LONG_LINE for details.
> Check your line lengths to see if they're 78 rather than 76 characters,

They are 77 characters. 76 of data, and 1 for the "=" sign.

DevilsPGD

In message <4f0dcbb0$0$9674$c3e8da3$1cbc7475@news.astraweb.co m> someone
claiming to be JF Mezei <jfmezei.spamnot@vaxination.ca> typed:

>DevilsPGD wrote:
>
>> Well there's your first problem: Required=2.0 is insane, and will cause
>> such a high false positive rate that he may as well not bother checking
>> his Inbox and just use the Spam folder as his primary Inbox.
>
>Interesting. Yet, this terrible setting did cause me to realise that the
>MAIL.APP on the iPhone sends out 77 character lines. (when you include
>the = sign)

Yup. However, not much you can do about it.

>Since the offending SMTP server belons to a large australian ISP, I am
>not really in a position to tell them what to do :-)

Why not? Whoever they've hired is not particularly competent, it sounds
like they could use the help.

--
It's always darkest before dawn. So if you're going to
steal your neighbor's newspaper, that's the time to do it.