In an ideal world drafting poignant email copy, designing wonderfully branded email templates, and crafting succinct and enticing email subject lines that get open and click-through rates skyrocketing, would be enough to make your client email campaigns a roaring success.

But before hitting send, have you even considered whether your subscribers will get the opportunity to read your email? You’ve probably never thought much about the different aspects that determine whether your email makes the inbox or not.

But it needs some thought. It’s getting harder to get emails delivered, and spam blockers are getting tougher. There are a host of things you may not even know about that can prevent your email from ever reaching someone’s inbox.

Like expert ninja’s tasked with protecting the honour of the inbox, spam filters introduce yet another hurdle in the sales funnel. There are two main reasons your emails can get sent to the spam folder:

  1. Emails are flagged by a spam filter. Each email provider has their own top-secret filters.
  2. A recipient marks your message as spam. If a reader doesn’t like your message – even if they opted-in – they can send it to the spam folder themselves. If enough people do this, email providers are more likely to classify messages coming from you as spam in the future.

There are a number of rules you can follow to reduce the chances of your emails hitting the spam folder. Some of these are technical, some are content driven and some are even enforced by law. But if you are being honest, relevant to your reader, showcasing yourself in the best light and adding value then you are already half-way there. So here are some top tips to defeat the spam warriors and improve your email’s deliverability.

Tackling the technical

Do – announce yourself

Because people are so inundated with spam, they alarm bells ring as soon as they see an email from unfamiliar senders. Make sure recipients can recognise you as the author by using your brand name. Better yet, send the email from a real person – because they are too. Recipients are typically more likely to trust a personalised sender name and email address than a generic one. just won’t cut the mustard.

Do – test, and test again

At the risk of teaching granny to suck eggs, always send yourself a test version of the email before you send it out en masse. It’s not rocket science. If it goes straight to your spam folder then you need to re-evaluate your message and your tactics.

Before sending emails out to your entire list, it’s also worth the time to utilize a spam checking service. offers a free downloadable tool for Windows that uses Spam Assassin to check. If you prefer to avoid downloading any software, you can send email to the service and they will also check a few other items important to email deliverability or uses a form based solution to test emails.

Do – use a good email marketing tool

There are a shed-load of email marketing providers out there including Mailchimp, Groupmail and Constant Contact.  All good email marketing providers will have a reporting dashboard containing metrics to monitor your campaigns.

Whatever platform you use, make sure your data is good! Even if your list is entirely built on valid opt-ins, you are at risk of being branded a “spammer” if you don’t practice proper email hygiene. Why? Because internet service providers base complaint rates on active subscribers, not total subscribers.

Whether your campaigns make your subscriber’s inbox or not, largely comes down to previous engagement with your campaigns. If they’ve opened and clicked on your emails, then your next campaign is likely to make the inbox. If on the other hand, they’ve deleted them without opening them (how dare they), it’s more likely your latest campaigns could end up in the spam folder.

Do – get email sender accreditation from a third party

Sender accreditation by third parties such as Sendgrid and Amazon, provides another level of attack on spam filters.  Accreditation will mean that you are required to follow certain usage guidelines from those third parties.  So what do you get in return? In short you are listed in a trusted directory that ISP’s reference to allow certain emails to bypass email filters

Do – use segmentation to send targeted, relevant campaigns

Rather than sending the same email to your entire list, try segmenting your list and targeting the campaign to those who you know are going to be interested. By doing so, you’ll increase the number of recipients opening your campaigns and decrease the number of people deleting them. This means a lot of love for you from those hard to please email providers.

Do – get on your subscribers’ white list

Nearly all email providers like Gmail, Outlook, Yahoo, and your own ISP, allow you to add specific email addresses to your contacts database (whitelisting). Emails sent to these addresses typically bypass the spam folder and are delivered straight to the inbox.

The easiest way to reliably get into your subscribers’ inbox is to ask them to add you to their contacts list.  Why not try sending a welcome email inviting them to do so:

Do – ask twice

Double opt-in means that after someone subscribes to your email list, you send them a follow-up email with a confirmation link ensuring they actually want to receive email communications from you.

Users that have to confirm that they want email communications from you are the ones that will fully read and engage with the emails they receive. When you use double opt-in, your email lists will be much more qualified and your subscribers much more engaged.

Do – provide an out

Make sure you have a clear unsubscribe link in your email Just because someone has subscribed to your list in the past, it doesn’t mean they will always be interested in what you have to say.

The most common place for these unsubscribe CTAs is in the footer of your email, so users tend to know to look for it there — which makes for a better user experience. Don’t try to hide your unsubscribe link or use a really small font. If you make it easier for your reader to click unsubscribe than to mark your email as spam, then your sender reputation will reflect this.

Sure-fire ways to end up in the spam box

There are tons of fundamental technical mistakes people make in sending emails – you are not alone! This whistle stop tour of the main offences I’ve mentioned by Sir Spamalot, alongside a few others below should help set you on the right path to inbox victory:

  1. Don’t email people who have bounced repeatedly
  2. Don’t use video, Flash, or JavaScript within your email
  3. Don’t embed forms in your emails
  4. Don’t include attachments
  5. Don’t use irregular fonts, colours or sizes
  6. Don’t use large or overwhelming numbers of images
  7. Don’t hide text (that would normally trigger filters) in an image

Killer Content – kicking the inbox defenders where it really hurts

DO – Take time on your subject line

How you compose your subject line in your campaigns is a huge factor in whether or not you get a high open rate, get ignored, or get marked as spam. 33% of recipients base their decision on opening an email on the subject line alone.

First off, the choice of language is very important. There are certain words and phrases that will trigger spam filters and get your mail sent straight to where you don’t want it to be. A good rule of thumb is this: If it sounds like something a used car salesman would say, it’s probably a spam trigger word. Think “free,” “guarantee,” no obligation,” and so on. Hubspot has a great list of trigger words by industry so check it out.

Instead of using these trigger words, be creative, interesting and informative – without giving too much away. Make them feel special – the effects can be magical –use terminology like “An exclusive offer”, “My gift to you” “you’re invited”. Keep in mind subject lines should be concise – you know how quickly people scan an inbox. Try swopping Newsletter or Update out of your subject lines and try:

  • John, you are about to miss out on an amazing offer
  • Happy Birthday Lindsay – your surprise is inside (Awesome personalisation and timing double whammy!)

Subject line DON’Ts:

  • Write subject lines in capitals. This is shouting and is just plain rude
  • Make spelling mistakes
  • Swear
  • Use exclamation marks – especially lots in a row!!!!!!
  • Use one-word subject lines such as “Hi.”
  • Try to sell
  • Be impersonal. Include their name in the “To” field
  • Have some dignity. Don’t plead with the reader to “Open me!” or “Read me”
  • Don’t use Re: or Fwd: to trick the reader into thinking that they have already spoken to you about a certain topic
  • Don’t make false claims

Do – offer both HTML and plain text versions

Plain text emails are simply emails without the bows and frills, while HTML versions use design elements that give you better visual impact. By sending both versions of a single email you are putting up your hands to say to email providers “Yes that’s right I am a legitimate sender”.

You don’t have to be a coding expert or techy genius to prove your authenticity as a sender.  Thankfully, most platforms will let you easily create both versions within their email editor.

Do – keep emails short

Too much copy is like a red flag to a bull for spam filters. Not only that, but people generally like concise emails better. Everyone’s busy and their inbox is already full, so why make things worse? The rule of thumb is that 500 words are about right. One of the best ways to keep things short and sweet is to write like a human not a robot stuffing as many keywords in as possible.

Make sure any information you want the reader to see stands out with clear headers and break down the text into small clear paragraphs.

Do – balance text and Images

Some of the best performing emails use strong imagery to great effect – but the key is balance – ensure your email has enough context to deliver your message even without them. Mailchimp flagged, “too many images, not enough text” as the top reason their emails set off filters. A maximum 60/40 text to image ratio is a commonly recommended upper limit.

Many email providers and desktop email clients like Outlook block images as standard anyway, so depending on your user base, you may want to consider if sending your image is worth the risk at all.

If you do use them, use of alt text (that is shown even when images are turned off) is always recommended. You can add this in your email tool’s rich text editor – just right click the image and off you go.

If you want to win the inbox war, act like a winner.

So how can you make sure people are interacting with your emails and sending positive vibes to inbox providers? In short – don’t look like spam. By putting these top tips into practice and offering great content, exclusive offers and having prominent subscribe opportunities that make it easy to join your list, your next email campaign is sure to hit the target. When all is said and done, staying out of the spam box and heading straight to the inbox requires you to do just one thing: be a human. Act like a human talking to another human when you send emails. Treat their inbox the way you want yours to be treated.