I'm not comfortable with posting the IP address here - only because I don't understand the implications. That is, I've always thought IP addresses were something to be protected.
Nope, IP addresses are nothing to be protected. They are attached to every email you send, every comment you make on a forum, and every Web site you visit--they're public knowledge. There are no special security implications, and if you're on broadband they probably change all the time anyway. For example, my IP address at the moment is 71.59.249.181, which belongs to Comcast.
I don't mean to be a pain but I still wonder about the GIF. If I (or anyone else) wanted to create a GIF to dress up our email, is it possible to create it in such a way that it causes ISP spam filters to think there's something wrong with the mail?
Some spam filters weigh emails with attached images very heavily toward spam, because many spammers attempt to evade detection by sending emails which contain random words or phrases, and the actual "advertisement" in an attached GIF. (This is especially common among phony pharmacy spammers--the ones who sell fake pills that they claim are Viagra--and among pirated software spammers.)
You can examine the headers of an email in Mail by using the View->Message->Raw Source command. You'll see a lot of what looks like gibberish at the start of the message. If you read closely, you'll also probably see some headers inserted by the spam filtering software. For example, here's an actual spam message that was flagged for me by my spam software. The parts of the header that show the spam scoring information are in bold. I've removed my email address and replaced it with (removed).
Return-Path: <bonnetuhv44@seedrack.com>
Delivered-To: (removed)
Received: (qmail 30121 invoked by alias); 7 Jan 2010 13:04:50 -0000
Delivered-To: (removed)
Received: (qmail 30112 invoked by uid 210); 7 Jan 2010 13:04:50 -0000
Received: from 122.167.130.171 by se1 (envelope-from <bonnetuhv44@seedrack.com>, uid 201) with qmail-scanner-1.25st
(clamdscan: 0.88.7/10267. spamassassin: 3.1.3. perlscan: 1.25st.
Clear:RC:0(122.167.130.171):SA:1(6.9/5.0):.
Processed in 13.954543 secs); 07 Jan 2010 13:04:50 -0000
X-Spam-Status: Yes, hits=6.9 required=5.0
X-Spam-Level: ++++++Received: from unknown (HELO ABTS-KK-Dynamic-171.130.167.122.airtelbroadband.in) (122.167.130.171)
by (removed) with SMTP; 7 Jan 2010 13:04:35 -0000
Received: from 122.167.130.171 by seedrack.com; Thu, 7 Jan 2010 18:34:18 +0530
Message-ID: <000d01ca8f99$ebba16d0$6400a8c0@bonnetuhv44>
From: "Manager Darcy Conrad" <confirmation@myspace.com>
To: (removed)
Subject: SPAM: HIGH * MySpace Password Reset Confirmation! Order NR.3944
Date: Thu, 7 Jan 2010 18:34:18 +0530
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0006_01CA8F99.EBBA16D0"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 4.71.2244.8
X-MimeOLE: Produced By Microsoft MimeOLE V4.71.2244.8
In this case, the spam scanner is showing that it uses a score to determine spam, and that the score is determined by looking at the message and comparing it to "spammy" messages. The minimum score that it needs to tag something as "spam" is 5.0 and this message scored 6.9, meaning the spam software is very confident that it is spam.
Some spam software provides even greater detail, specifying exactly which parts of the message caused the email to be flagged.
