Transactional emails are often dubbed “the emails your recipients want to get.” Contrary to marketing emails, not everyone is on the edge of their seat waiting for it to hit their inbox. Sometimes, however, even your transactional emails can be marked as spam. And the more spam complaints your domain gets, the lower its reputation. The lower your domain’s reputation, the lower the chances that inboxes (like Gmail or Outlook) will accept your following email. Let’s look at how that works and how you can prevent your following email from landing in the spam folder.

What is a complaint?

From the moment your emails have been delivered to an inbox, recipients can mark them as ‘unwanted’ or ‘spam’. Often, the inbox provider sends feedback to the original sender (e.g., Flowmailer) about this action – a so-called feedback loop. The more these markings, the more alarm bells will ring at these inbox providers’ spam filters.

Complaint Rate

The total sum of spam markings (or: complaints) should never exceed 0.03% of your total amount of transactional emails sent. The industry benchmark for marketing emails is <0.1%. This percentage is what we call a complaint rate.

The complaint rate is calculated by dividing the complaints by the messages delivered to your recipients’ inboxes. So, if you’re sending out 100,000 emails per month, 3000 spam complaints are the maximum amount of complaints you should statistically get.

Though three thousand people hitting “spam” on your emails sounds like a lot, there are a few reasons why they would.

What makes recipients hit ‘spam’?

Over the years, we’ve seen plenty of reasons for people to hit spam on marketing and transactional emails. Though it seems more evident for marketing emails, with subliminal reasons such as brand fatigue, transactional emails have been marked as spam quite a few times by their recipients. Often unaware of the consequence of not receiving emails from your brand at all, there are five distinct reasons why people mark your transactional emails as unwanted:

  • Informational vs. commercial ratio is off;
  • There is no other way to unsubscribe from the emails;
  • You’ve hit a spam trap;
  • They don’t want to pay;
  • They’ve hit ‘spam’ by mistake (that happens!).

The informational versus commercial ratio is off

We love a beautifully designedtransactional email with cross-selling opportunitiesand highly personalized content, as long as it meets the golden ratio of 80% transactional and 20% marketing content. Marketing can help a recipient take the action you want them to take, but when a transactional email feels too sales-y, people will mark the email as spam.

No other way to unsubscribe from the emails

Many transactional emails are sent from various systems without a (working) way of managing preferences. We’ve seen many triggered / system / transactional emails we did not want to receive anymore but could not find a way to unsubscribe. You don’t have to put an unsubscribe email in a transactional email – but it’s always better than people marking you as spam.

Hitting a spam trap

Another reason for getting marked as ‘spam’ is when you hit a spam trap. Spam traps are (abandoned) email inboxes that are now dedicated to eradicating spam emails. They were once functioning email addresses but have not been used for years at are now taken over by someone who will mark every incoming email as spam. Good data hygiene is therefore of great importance, both on the lead capturing side as well as with existing customers.

Customers don’t want to pay

Though it sounds a bit far-fetched, the highest spam complaints we see are typically on legitimate invoice emails. It’s not uncommon for this type of email to go over the 0.03% complaint rate. There’s nothing wrong with the email; the recipient doesn’t feel like paying the invoice. And if you don’t have the email, you don’t have to pay… right?

Recipients marking emails as ‘spam’ by mistake

This happens more often than you might think. It’s happened to us more than once, too. However, this can never be the sole reason your complaint rate is over 0.03% – unless you’re sending to just 30 people. These recipients will most likely remove the spam flagging after reaching out to them.

Gain insights in and fix your complaint rate

With a diaspora of email flows, it can be hard to keep track of your complaint rates – if the sending systems provide those at all. Given that we’re not all email administrators, you can easily get lost in the data when diving into the statistics and determining if your complaint rate is up to par. In Flowmailer, you can easily connect sources, overview your deliverability data (including complaint rate), and view message details. Below’s an overview of the message details you can view on our platform.

Message details of a SPAM complaint

Act on complaints

To keep your complaint rate as low as possible, you have to act when your complaint rate is inclining. A steady complaint rate of up to 0.03% is nothing to worry about, but when it increases for no apparent reason, you’ll need to investigate the issue. Here are a few things you can do in Flowmailer to investigate your complaint rate:

  1. Check if the complaints are coming from a specific source (e.g., your invoice flow);
  2. Check what triggered the email;
  3. Check if the email addresses look legitimate;
  4. Check if the email has been opened or not;
  5. Check if there’s a good unsubscribe/preference flow;
  6. Check if the content of the emails that are marked has changed;
  7. Check if your message details are recognizable enough.

These checks should give you an idea of your scenario and how you can act upon it. When you find out where most of the complaints come from, you can optimize the funnel of those emails; from form fill to feedback management. In any case, it’s good to follow best practices on transactional email design and deliverability to prevent a high complaint rate. If you have questions about your (increasing) complaint rate, feel free to contact our professional services team!

Why recipients mark your transactional email as SPAM

There’s a bunch of reasons why recipients would even mark your transactional emails as spam. Though there are specific messages that can cross this line, 0.03% is the maximum complaint rate you should get on your emails. By monitoring your email streams, with a platform such as Flowmailer, you can prevent this from becoming a problem to your deliverability.