1. Only get the right opt-ins

One of the most common reasons for recipients to mark your emails as spam is that they consider them to be err… spam. It doesn’t matter if your messages are truly unsolicited or not, if the recipients believe them to be they will be reported as such. 

That’s why when gathering opt-ins first of all you have to make sure the email address provided truly belongs to the person that signed up for your emails. Using a double opt-in system (where you ask recipients to confirm their subscription through a link in an email) enables you to make sure that someone didn’t make a typo or signed up using someone else’s email address. 

Also, avoid surprises and make sure that it’s clear what someone’s signing up for. What kind of information can he expect? How many times will he receive your emailings?

You might scare of some opt-ins this way, but that’s no loss to mourn. You’d rather have one opt-in that really wants to receive your emails, than ten that discard them as spam because they weren’t what they expected. 

2. Be recognisable

Another common reason for people to mark emails as spam, is that they don’t recognize the sender. Always make it perfectly clear to your readers who you are. Using just an email address is the worst mistake you can make.

So don’t just use info@company.com, rather go for Company X if you don’t want your newsletter to end up in the spamfolder. 

Besides being recognizable as a sender, you should also be clear on the content of your email. The email pre-header (also known as snippet) can help you do so.

In a lot of cases, email pre-headers contain text like ‘Can’t read this mail? View the web version,’ or ‘You are receiving this email because you signed up for…’ And while this is crucial information to include in an email, don’t put it in the preheader. Rather go for a line that tells the reader what’s inside the email.

3. Don’t hide the unsubscribe button

Hiding the opt-out somewhere in small print in the corner of your newsletter might seem like smart plan. But it’s actually a very bad idea.

The only thing that’s worse is not including an opt-out link at all. Whenever recipients don’t want to receive your emails anymore but can’t find an subscribe link, they are very likely to hit the spam button instead. 

4. Don’t use a no-reply address

Some people don’t look for an opt-out link but send a reply message telling you they don’t want to receive your emails anymore. 

But as soon as they see that replying to you isn’t possible (either because your address starts with no-reply, or that their emails bounce), don’t expect them to search for an opt-out link in your email. The first thing they’ll probably do is click the spam button instead.

5. Ask inactive recipients to renew their subscriptions

Somebody that signed up for your newsletters might not be interested in your emails anymore. Maybe he changed jobs, or maybe he just lost interest. There are various reasons why opt-ins expire, but it’s always important to remove these expired opt-ins from your email list. 

People that are no longer interested in your emailings lower your open rates. And while that in itself isn’t very good for your email reputation, of course uninterested opt-ins also reduce the risk of reaping spam complaints. 

Monitor your emailings for recipients that haven’t opened your emails for a while, and send them an email asking them if they still want to receive your messages. Send a reminder if you don’t get a reply. Still no reaction? Consider this address to be an opt-out. 

Bonus tip: Sign up for feedback loops

Feedback loops are programs that enable senders of large amounts of emails to directly process spam complaints as opt-outs in their database. Email clients like Hotmail/Outlook and Yahoo! offer this service for legitimate businesses, where they send  back a message to the email sender whenever the message is marked as spam by the recipient.

Of course signing up for a feedback loop won’t prevent a spam complaint from being registered in the first place. It will however ensure that you stop sending emails to someone that has marked them as spam.