Malware

10 ways to keep your messages out of spam filters

Legitimate messages that get snagged by spam filters can lead to big problems -- such as derailed job searches, hard feelings, and lost business. These tips will help ensure that your messages reach their intended targets.

Most spam filters use a scoring system. Each offense has a value. The higher the sum of a message's offenses, the more likely a spam filter will reroute the message (or not delivered at all). A lone offense usually isn't enough to flag a message as spam; it takes a combination of violations to score high enough to meet the level of true spam. But the system isn't perfect, and sometimes overzealous filters flag legitimate messages as spam. Applying the following do's and don'ts will help you ensure that your legitimate messages pass the spam filter test and reach their intended Inboxes.

Note: This article is also available as a PDF download.

1: Do curtail your excitement

Specific words and phrases are the number one hook for spammers, and that makes them the best tool for catching spam. Discussions of large sums of money and amazing breakthroughs top that list. Offering a money back guarantee or a way to save money -- Why pay more? -- may be part of a legitimate offer, but it will set off spam alarms. Your message might excite you, but multiple exclamations points will also excite spam filters. All uppercase characters might convey your enthusiasm, but they'll also set off spam filters. Just using the word urgent is enough to put a spam filter on alert.

Avoid using words and phrases that trigger spam filters. You don't have to memorize a long list, just visit a few of the Web sites that maintain lists of spam keywords. Use the phrase "spam keywords" in your favorite search engine and you'll get plenty of hits. Look for current lists, as the keywords are updated regularly. It's okay to share good news and special offers with associates and clients. Just bypass all the hype.

2: Do use plain text

An email that consists of all HTML or all images and links will trip a spam alarm. HTML is certainly okay, as long as it's good code and it doesn't comprise the entire message. Sloppy HTML code is also an easy giveaway for spam.

Go ahead and use good HTML code but also include as much plain text as possible. That's a clue to the spam filter that the email is legitimate. Besides, you'll want to accommodate recipients who choose to view the message in plain-text format.

3: Don't include attachments

Avoid attachments when possible. Spam often contains destructive attachments, so filters tend to overreact to an attachment. Links are a better alternative, if feasible.

4: Do check your sender score

A sender score grades your reputation as a sender. Your average business or personal account probably isn't going to learn much from this score. Businesses that rely on frequent email campaigns will. If that includes you, check your sender score often and be proactive about repairing damage. A bad reputation can result in email being filtered, regardless of content.

5: Don't send spam!

If you maintain a large list, for marketing -- for any purpose really -- make sure the members of your list want your email. Sending spam will get your domain and your business blacklisted and it's difficult to get off those lists. Once you're on a blacklist, most spam filters will snag your mail, regardless of its content. Remember, your reputation is important as your message (#4).

Hint: Exchanging business cards is not an invitation to send spam unless that condition is made clear during the exchange.

6: Don't use colored fonts

Black type seems boring, but in truth, it's easy to read and looks professional and clean. Don't be fooled into thinking that colored fonts will create eye-catching opportunities to promote your message. They might, but they'll also excite spam filters.

7: Do test your recipient list

When you send an email or newsletter to a list, test the message in as many client applications on as many operating systems as possible. Simply send the message to yourself or to a test account and retrieve it on several machines using different operating systems and email clients.

8: Don't use the word test in your test message

When testing an email or newsletter (#6), don't use the word test in the subject line. Most server filters will snag the message, regardless of the message's content. You'll waste time trying to fix the content when that single word may be the culprit.

9: Do compose a succinct subject

Your subject line should be as specific as possible. Smart filters assume that spammers can write a reasonable subject line. What they'll lack is detail. The more specific your subject is, the better. For example, the subject Tomorrow's Project Meeting is reasonable but generic. A better subject might mention the time, the meeting room, and so on. Don't go overboard, but include details if possible.

10: Do rely on professional experts

For most of us, a legitimate message that's snagged by a spam filter can mean lost business or at the very least, hard feelings. These tips aren't meant for professional online marketing operations. If you're considering an online marketing campaign for your business, don't wing it! You could inadvertently damage your company's reputation. Hire a professional who specializes in online marketing to keep you on the right side.

About

Susan Sales Harkins is an IT consultant, specializing in desktop solutions. Previously, she was editor in chief for The Cobb Group, the world's largest publisher of technical journals.

12 comments
lkarnis
lkarnis

I work for an antispam company. Here are some other things you should do to help ensure your e-mail is not blocked... - Make sure your Mail Server has a DNS name and that your DNS names resolve both forward (name->address) and backward (address -> Name) - Make sure you have an SPF (Sender Policy Framework) DNS record that authorizes your mail server to send e-mail for your domain - Do not set up an unauthorized mail server on a retail broadband connection. The SpamHaus PBL list identifies netblocks not authorized to send e-mail and your messages will end up in the junk mail folder - Set up Domain Keys if you do large volumes of e-mail - Do not send any 'dangerous' attachments (.com, .bat, .exe, etc.). Zip them up and then send them - Do permission based e-mail marketing. If you send first and ask questions later, you'll end up on a black list - Get your own mail server on its own IP address. Often community mail servers get black listed because of something someone else is doing (from another domain) - Always include opt out links. It's the Law (Can-SPAM act) - Never lie/miss-represent your e-mail address or domain name or you will be black listed - Never e-mail promoting anything illegal, immoral or unethical. You will be black listed. Remember, it may be legal where you are but illegal elsewhere Could go on, but you get the idea. Larry

oldbaritone
oldbaritone

Subject: Always include a legitimate subject line. Messages with no subject are often trashed as spam automatically. Domain: Send your messages from a domain that does not give away free throw-away email addresses. Messages from domains like hot..., g...., .ru and others have a more difficult time because those domains have developed a reputation for being major sources of spam. Many spam filters consider those domains automatically suspect until proven otherwise.

dregeh
dregeh

I've seen that a lot in many of the emails I receive. I think I read that once too, but I haven't found any advice to substantiate it.

harrylal
harrylal

Wonderful tips on how to more effectively spam. I just love the disclaimer with #10, that will definitely stop them...

douglas.gernat
douglas.gernat

Wish I could hand this off to some of my clients. Fighting their sender reputation and NDR's is exhuasting!

seanferd
seanferd

Advice cannot substantiate anything, this is the job of evidence. There is certainly no implication at all that adding an unsubscribe link will tend to identify your message as not spam. Benefits of unsubscribe links: As the mailer, you may be easily notified that a recipient no longer wishes to receive mail from you. Recipients will more likely have a more positive view of you if you provide one along with a brief sort of apology in advance. As a recipient, this allows you to unsubscribe easily. Self explanatory. As a spammer, including an unsubscribe link is an exercise in social engineering. Recipients clicking that link let you know you have found a valid email address.

sissy sue
sissy sue

You would make a great editor. I bet there weren't many other readers who caught that.

pgit
pgit

you see both on TV all the time. Good tips here, Susan. I'll keep a link to this handy to send to people who should heed one or two of the points you make. One more point I would add regards forwarding. Avoid forwarding if possible. But if you must, for God's sake delete any email addresses showing in the body of the thing. I find a lot of messages people have wanted tossed into the trash, I have assumed for containing anywhere from a dozen to upwards of 100 email addresses showing in the clear. I emphasize I have always assumed this, I don't know if there's actually a filter triggered by this. (it could just be the "Fwd: [Fwd:] [Fwd:]..." crap in the subject line)

dregeh
dregeh

seanferd has weighed in. thanks Sean. For anyone else interested... Here's a little background for my scenario. I run a website. My website has a "join our group" page where a person can submit their email and some info, and a message is sent to the people in our group who handle newcomers. The message that is sent to our own people who handle the newbies sometimes gets caught in their spam filters. The reply email is no-reply@ourwebsitename.com. As I mentioned, I see email from other websites that have this unsubscribe link within, and as I also mentioned I believe I have read advice (as this column is giving) stating that adding the unsubscribe link is a factor for spam filters. I'm looking for all possible ways to fix this.

ssharkins
ssharkins

Not all professionals are experts; not all experts are professionals. Sorry guys, I have to disagree with you on this one. :) I'm a Master Gardener -- I'm not a professional landscaper/gardener/anything in the industry. I don't make a living from it, but some would consider me an expert. However, no one will ever call me stubborn, so in an act of compromise ()... there probably aren't many amateur "online marketing" experts. :) But, I was trying to make a point... go with someone who's doing it for a living, not your neighbor/uncle/kid who says s/he knows all about it...

NickNielsen
NickNielsen

An expert can be either a professional or an amateur. One of the most expert electronics techs I've ever known did it as a hobby. I'm a professional, but he was the expert. It was the sequence more than anything; "expert professional" doesn't jar quite as much as "professional expert."