Occasionally your correspondents may tell that messages you have sent have been detected as junk mail or “phishing” by the recipient’s email program, such as Outlook 2007 or Windows Mail. This is principally a problem with the receiving software, and here we describe a few things you can do to reduce the likelihood of your email being misclassified as suspicious. However, such “false positives” are not related to anything GreenNet does and the recipient might like to consider reconfiguring or changing their anti-spam software.

Unless you have an obscure email address that has never been posted on the web, you are probably using multiple anti-spam systems, both by your ISP (GreenNet), and maybe in your email program or a firewall. More layers of anti-spam mean more potential for false positives, without necessarily increasing the detection rate of spam that much. Spammers try to avoid some obvious ways of being caught, and as a result anti-spam systems have to widen their net, sometimes trapping innocent correspondence in the process. Thunderbird and Mac Mail have junk mail filters you can train, but the anti-spam facilities of other email programs, such as Microsoft Mail or Outlook 2007, are probably superfluous when a decent ISP filter, such as GreenNet’s, has already been applied by the recipient’s ISP. “False positives” are much more likely to be due to issues with the sending email program or the receiving email program, than they are with the ISP, through which the message passes mostly unchanged.

Simple text false positives (Outlook)

Advance fee frauds are often sent through valid email hosts and are difficult for anti-spam systems to distinguish from genuine email. Therefore anti-spam rules can be too wide. For example, the following text is usually enough for Outlook 2007 to mark a message as spam:

A prize has been awarded to Beatrice and Mr Jones also won.

This is presumably a measure to block lottery fraud spam. One can’t be expected to know all the phrases a closed-source program regards as spam, but it might be sensible to be conscious of wording when discussing something like the economics of West Africa. See below for how a recipient can add you to their safe sender list and turn off Outlook mail filtering.

Windows Mail and CA Personal Firewall

CA Personal Firewall has a pop-up blocker that adds an invisible script to incoming email. When you reply to the mail, the script is still there, and Windows Mail marks this as a phishing scam. The code added (which you can see by viewing the message source) is:

<SCRIPT src=“http://127.0.0.1:37935/xpopup.js” type=text/javascript>  

There are two possible ways to stop this happening if you have CA Internet Security Suite installed:

1. Turn off the pop-up blocker. Open the CA Firewall, go to Privacy > Pop-up Blocker, and turn it off or set the slider to Custom and untick ‘PopUp ads’ and other features. Close CA firewall. OR

2. Turn off sending of HTML email in your email program. This will mean you cannot send emails with bold lettering or embedded pictures for example, but that usually isn’t a problem. For Outlook Express, go to Tools > Options > Send tab, then make sure “Reply to messages using the format in which they were sent” is not ticked, and under “Mail Sending Format”, click “Plain Text”, and “OK”.

Windows Mail and Windows Live

Certain other types of link can cause this issue, for example, ones with a proprietary protocol like

wlmailhtml:%7bA0B874C8-....:http://www.gn.apc.org  

These are apparently added by Windows Live mail, and don’t work in other contexts. Windows Mail regards them as a sign of phishing. Just typing a link in an email program is the safest way, and only adding necessary links should reduce chance of being misclassified.

Outlook 2007 and dotted user names (firstname.lastname@example.org)

If you are using Microsoft Offfice Outlook 2007 to send email, as well as being careful that links you include work correctly as mentioned above, there can be a problem with the invisible message-id header. This is a bug in Outlook 2007 that only triggers if you are sending from an address with a dot before the ‘at’ sign. The header created then wrongly contains multiple at signs like:

Message-ID: <012301c889bd$18b3cd00$4a1b6700$@lastname@example.org

This has been reported several times on Microsoft’s own newsgroups in 2007, 2008, later that year and now 2009, but there hasn’t been any fix or other reaction from Microsoft’s Outlook programmers.

If you want to avoid your mail being treated as spam, the choices are to request an alias that does not include a dot, probably firstnamelastname@example.org or just firstname@example.org and set your Outlook to use that; or alternatively switch from Outlook to a different program for sending email, such as Thunderbird. In theory we could fiddle with the outgoing message as it passes through our servers to correct the faulty Message-ID header, if you request this for a particular domain.

Remove any spam text from quoted message

If you forward spam or something spam-like, and add your own message to it, then it’s still quite likely to get classified as spam. In these days when top posting is common, it’s possible to forget the unnecessary and probably irrelevant material that you are accidentally forwarding. It’s another good reason to trim excessive quotes from the bottom of your replies.

Ask recipient to turn off MS junk mail filters or add you to Safe Senders

Microsoft’s own instructions for Outlook 2007 users recommend periodically checking for false positives; and suggest what to do when they are found, including adding the sender’s address (possibly yours) to the program’s safe senders list . As mentioned above, if someone gets relatively little spam it may be better to turn it off altogether.

Windows Mail anti-spam default setting has been described as a ‘trifle drastic’, and that link includes instructions for turning it off. If the recipient needs to keep the Windows Mail junk filter on, they can select one of your messages, then click ‘Message’ > ‘Junk e-mail’ > ‘Add Senders’s domain (e.g. @gn.apc.org) to Safe Senders list’.

Microsoft recommends updating Outlook message filters regularly, but feedback on that page seems to suggest that particular updates may also cause additional problems, one would hope temporarily.

Investigating further

Although the main action is up to the recipient, we can look into cases when outgoing email from a member of GreenNet has wrongly been marked as spam or misdelivered. The most useful information would be a copy of the message as received, to be sent as an attachment directly to support@gn.apc.org. We can then communicate directly with the sender and their email provider if needed. If the email has not been received at all, we need the date of the message and the sender and recipient address.

You might like to send your contact a short message with a link to this page.

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