Do your emails have a low bounce rate, yet they are not being opened and the calls-to-action are not being clicked? This is most likely due to the subject of the emails – in two ways. First, it’s possible that the subject simply doesn’t generate enough interest, so the emails disappear unread into the trash.
On the other hand, it may be that the subject does a lot of things right (i.e., it is concise, engaging, and inviting), but that is precisely why it does not reach a recipient’s inbox at all, but instead is classified as spam by the recipient’s mail program. This is because the line between catchy, advertising-friendly wording and suspicion of spam is narrow and often depends on individual trigger words that fit into the grid of the respective spam filter. Therefore, here is a list of precisely these terms that you should rather do without in your email marketing.
The subject line is everything
It’s frustrating: a well-worded email about a great product will most likely not be read if the subject line doesn’t fit. This in turn leads to a correspondingly low „inbox placement rate“: the sent mails arrive in doubt, but do not reach the inbox, but end up automatically in the spam folder.
However, an e-mail subject must not only survive automated spam filters, but also the recipients‘ selection process. After all, 69 percent of users say they classify an email as spam based on the subject line alone. Conversely, 47 percent open a mail solely because of a promising subject line.
So what should a subject line look like that appeals to users? Above all, it must not be too long. A maximum of 60 characters is displayed in full by the various mail providers, in some cases it is even only 20 to 40. A scope of six to ten words is clicked on most frequently. In terms of content, it is purposeful to present briefly and concisely what the message is about, to arouse curiosity and attention, and to be transparent about the purpose of the mail. In addition, the subject should be taken up again in the actual body of the text.
It is essential to avoid dubious terms that are immediately associated with dubious portals and junk mail, such as calls to chat, make friends or gamble. Successful, on the other hand, are confirmations, check-ins and status information – in other words, all keywords that indicate (editing) progress and promise an update, because that’s what users are waiting for.
An additional difficulty: spam filters‘ schemes do not always match users‘ interests. For example, emails with the word „free“ in the term are opened ten percent more often, while at the same time the keyword „free“ acts as a trigger for many spam filters. In this conflict, however, the filters are clearly the more significant aspect: if they are not bypassed, users will not get the chance to respond to an interesting subject at all.
In order to achieve this, an inflationary use of capital letters and punctuation marks (especially exclamation marks) or excessively long sequences of digits should be avoided as a matter of principle. But also very specific words inevitably trigger the spam filters, even though they are used with the best of intentions. You can find a large part of these terms in the following list:
You should refrain from using these terms in your mails in order to avoid ending up in spam.
These terms trigger spam filters
The list of spam words can never be absolutely complete and is mainly experience-based. The most comprehensive and up-to-date list for German no-go terms has been compiled by mailify, a platform for SMS and email marketing:
Free of charge, 100% free of charge, compensation, gift, refund, free of charge, sign up for free, test for free, profit
reduction, discount, best price, offer, special offer, compare prices, for only, not expensive, save a lot of money, voucher
credit card, bank card, investment, bankruptcy, sales, salary, interest rate, insurance, get out of debt, repayment, credit, cash, mortgages, PayPal, bonus, return, visa, mastercard
Category: earn money
Cash, money, easy, fast money, make money, extra income, profit, millions, save, best price, euro, profit, profit, be your own boss, €, $, £….
Category: No risk
guaranteed, 100% free, 100% secure, certified, risk free, offer, bonus, bargain, seen on TV, deal, it works, no rip off, no spam, no hidden costs, password, personal details
Dear friend, meet singles, please help, donate now, their family, teenagers, hello, do not delete, partnership
do it fast, right now, benefit now, limited offer, starting now, today only, don’t hesitate, grab it, expires soon
You won, bravo, click to receive your gift, exceptional gift, win, you have been selected, congratulations, reward
Sales, sell out, sell more, increase your sales, click here, order, job offer, sales figures, buy, marketing, increase
lose weight, lose weight fast, too many kilos, how to lose weight, diet, rejuvenation, soft food, erection, wrinkles, snoring, aging, baldness, without effort, endurance
valium, morphine, xanax, vardenafil, fluoxetine, viagra, online pharmacy, medication, medicine, therapy, doctor
Category: sex, drugs…
sex, meet, singles, hot, tart, weed, drugs, casino, blackjack, play money, movies download, streaming
Microsoft also officially announced back in 2009 that the following terms in the subject line are specifically classified as spam by Outlook:
Advertising, „!“ in combination with „$“ or „free“, $$.
Additionally, the following phrases are filtered as adult:
xxx, over 18, over 21, adult, adult only, 18+, erotic, sex, „free“ in combination with „adult“
Tips: What you can also do to avoid ending up in the spam folder
Even away from the choice of words, there are various strategies to ensure that emails end up in the inbox instead of the spam folder whenever possible. Because even if all trigger words could be avoided, that would be no guarantee that a mail would not be marked as spam after all. After all, spam filters also take other parameters into account. Therefore, you should additionally take these tips to heart:
Use automation features to send personalized emails at different frequencies. The better you satisfy users' needs, the less likely they are to mark your emails as spam, which would hurt your reputation with email providers. Run a spam test in advance - almost all email providers offer an explicit way to do this. In your mails, ask users to add the corresponding e-mail address to their address book. This is because obviously known e-mail addresses do not trigger the spam filter. Ensure that the bounce rate is as low as possible by maintaining an up-to-date contact list. This is generally an important indicator of spam. Pay attention to correct HTML formatting. Errors in this area are also quickly interpreted as spam by spam filters. Send mails exclusively via secure servers. This is guaranteed if the IP address of the sending server is listed on a list of registered and certified servers. Have your own IP address registered in a whitelist (i.e. a directory of senders not suspected of spam). The most popular ones are DNS Whitelist and The Spamhouse Whitelist.