Over the 10 to 15 years since email marketing became commercially viable, subscribers have told the email industry exactly what they like -- relevant email with content they want and expect -- and what they don't. But some email marketers still don't get it!

Look at how you read commercial email marketing. Getting unsolicited email probably bugs you as much as it does your subscribers. The other consideration is that the reading habits of today's digital consumers are changing. More and more consumers are reading email newsletters and offers in a social or mobile setting -- meaning the format and delivery must evolve too.

But aside from sending unsolicited email, what else are you doing that might alienate your customers? Here are seven deadly email sins you might not even know you are committing -- but they may be aggravating your customer base all the same.

1. Sending email they didn't ask for.

Why it's maddening: When people see your email, the last thing you want is for them to wonder, "Who is this?" or, "Why am I getting this?" or worse, "I knew I shouldn't have trusted them with my email address!"

Recipients will be most angered if they never knowingly gave you their email address to begin with, which would be the case if you snagged your recipients' email addresses from someone else's list or appended email addresses from a postal mailing list.

They'll also cry foul if they get email messages from you because they gave their email to another division of your company. Why? Because permission doesn't transfer. Unless you make it clear that signing up for one list means getting email from all your lists, don't assume that people will want everything you want to send them.

How to avoid: Tell subscribers why they're receiving an email and invite them to join your other lists. If your email contains relevant, high-quality content, subscribers will flock to your other lists. Maintain different attributes or lists for subscribers based on their described interests so you don't dump everyone into a general list. Also, just say no to other divisions that want to blast any email address they get their hands on, regardless of permission.

2. Sending unexpected email that's different from what they did ask for.

Why it's maddening: Suppose you sign up for a weekly email that promises to give you the inside scoop on trends in your industry. Sweet! But then, the email that comes is 10 percent industry trends insights and 90 percent product promotion. Off to the spam folder!

Your email isn't the only one in the inbox, and the days when people would race to open any email ended a decade ago.

How to avoid: Be honest about what you're offering at sign-up. If your email contains quality content and is relevant to your recipients' interests, people will want to receive your email and won't feel tricked when they receive them.

You can change the direction of your email marketing with past subscribers, but be upfront with them about what you're doing and what the value is to them.

3. Sending email that can't be deciphered on a smartphone or cellphone.

Why it's maddening: More people read or triage email on their mobile devices these days, but despite the hype, not everybody is reading your big, beautiful email marketing on an HTML-loving iPhone.

Putting all the key information like calls-to-action, unsubscribe, or contact info into one big image that doesn't render on most smartphones just wastes subscribers' time. Without a reason to keep your message, viewers will delete with a vengeance.

How to avoid: Put the value proposition in a short text message up front. If it's intriguing, readers might just keep that message around long enough to read it online.

4. Sending an email full of broken links and images.

Why it's maddening: It makes the message look "spammy" and untrustworthy. Those negative feelings extend themselves to the brands presented in the message and the company that sent the email. Broken links, broken images, or the wrong images -- not to mention the wrong call to action -- all waste a subscriber's time.

How to avoid: Build testing into the schedule of every campaign you run and don't let anyone rush you into skipping it. It's always faster to test your content thoroughly before sending it than to create an apology campaign, or to explain to the CEO why his mother couldn't see the picture.

5. Foiling unsubscribes with a complicated process.

Why it's maddening: First, it's illegal. CAN-SPAM says you can't hide the unsubscribe, make people enter a password, take a survey, or jump through any other hoops in order to get off your list. So, why do it?

Second, it will backfire. Maybe you think it's a clever way to keep email addresses on your list, but it doesn't work that way.

People who can't find the unsubscribe link or understand the instructions will just give up and click the spam or delete button. And, of course, when your next email comes, they'll click it again. Every time they do, it's another strike against your email sender reputation, which makes it harder to get your email delivered to those who do want to get it.

Also maddening: Sending email after subscribers have opted-out. Yes, CAN-SPAM allows up to 10 days to pull the address out of the database, but that's not an extra 10 days to pound them before they exit the list. It is, however, 10 more days they can report your email as spam.

How to avoid: Most email service providers (ESPs) nowadays have quick, efficient ways to allow subscribers to opt-out. If you need to integrate your data, discuss the matter with your ESP; it's a common issue, and your ESP will have suggestions and resources on how to keep your data in sync. (Read: Unsubscribing: Get More Out of "Goodbye")

6. Sending re-engagement email messages when they're already engaged.

Why it's maddening: Don't you hate it when you buy from a company's email, but the very next message it sends is a re-engagement request imploring you to come back and buy something? Or worse, offering what you just bought at a discount?

That emailer doesn't know who you are or how much you just spent on its products. It probably had the data to separate buyers and clickers from true inactive subscribers, but it just didn't use that information and instead sent a highly specialized email to its entire list.

It's lazy and unimaginative and will not improve a company's email marketing program.

How to avoid: A re-engagement campaign is a great way to spark new interest in old customers who need a boost to remember the value of what you have to offer. Such campaigns also help you gauge who on your list truly is deadwood that needs to be removed. Check your data carefully before you proceed, however, and make sure you're taking into account all of your touch points before you send that message.

7. Sending way more email than expected.

Why it's maddening: People sign up expecting to receive a certain amount of email, whether the frequency is stated in the newsletter name -- "Daily Candy" versus "Coupons Weekly" -- or in the copy you use to promote subscribing. Send more than you promise or imply, and you risk burning out your email list and generating more spam complaints or unsubscribes.

"Frequency creep" is hard to combat, though, especially if it comes via a direct order from your boss who doesn't have to deal with the carnage it can create in your email lists.

How to avoid: Set frequency expectations at opt-in and honor them. Put the frequency in the newsletter name. Allow yourself some latitude. If you want to expand mailings in a busy season, create a limited-time sub-list and invite current subscribers to add that list to their subscriptions.

Then, inform the sales manager who has issued yet another blast request that higher frequency can actually increase your costs and decrease your revenue through higher list churn. Explain to them that you'll have to spend more money replacing subscribers who fled your email list and took their future earning potential with them -- and that means less revenue overall, even with more email marketing going out.

Pleasing email subscribers is harder, but the payoff is better.

You don't have to be a dedicated student of email marketing analysis to know what bugs subscribers and what they like. Your own experience should guide you, along with what your clicks and conversions, unsubscribes, and spam complaints tell you. What makes you welcome an email or delete it in outrage? Apply those insights to your own email marketing campaigns. If you still find yourself scratching your head about why subscribers are unsubscribing or tweeting complaints about your email, ask them! Every unsubscribe is a real live person who may tell you what they want ... if you haven't already completely frustrated that person.

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About the Author

Wendy Roth is senior manager of training services for Lyris. She works closely with marketing professionals to help them use Lyris' solutions to achieve their highest online marketing objectives, and she collaborates with product development to ensure Lyris' products are based on marketers' changing needs.  This article was originally published on iMedia Connection. 

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