Spam Complaints Influence On Email Marketing Success

Open and click rates are the stats that most marketers monitor regularly, and rightly so. However, deliverability metrics such as bounce rates and spam complaints are just as important for tracking the success of your email marketing campaigns, maintaining a strong sender reputation and ensuring long-term deliverability.

A spam complaint is a reactive complaint from a recipient in response to receiving unwanted email. While the odd complaint is nothing serious, your spam complaint rate (the ratio between emails delivered and the number of complaints received) must be monitored for each campaign to ensure on-going deliverability and success.

Generally, recipients can alert their ISP or ESP, or the sender of the email of their complaints in two ways.

  1. The “one-click” spam complaint. This happens when a recipient clicks the "Report as Spam" button (or equivalent) from their web based email application. Some ISPs or ESPs will report these notifications to the sender, so that the email address can be removed from their lists.

  2. The “process-driven” complaint. Sometimes subscribers register their compliant by sending a copy of the unwanted email to their ISP or ESP (and sometimes the sender), to notify them that they consider the message to be spam. These complaints are significantly more serious. Usually in these instances, email addresses are not automatically unsubscribed and the sender has to unsubscribe or manually remove the email address to avoid sending future messages.

Calculating your spam complaint rate

Your complaint rate is calculated by dividing the total number of complaints registered, by the total number of emails sent for each campaign.

This ratio should always be less than 0.1% for all campaigns sent. A spam complaint rate above the accepted threshold will cause ISPs to route your emails to spam folders, block your emails entirely and possibly cause your IP address or domain to get blacklisted. The ratio should also be monitored to identify sudden spikes that push the complaint rate above 0.1%. In such instances, the entire process - from list collection to hitting send – must be reviewed to find out the cause of the problem.

Avoid spam complaints

So how does it happen that despite your best efforts to follow the rules, you are reported as a spammer and what can you do to avoid it? Simply follow good sending practices - consistently. The most common causes of spam complaints are due to bad sending practices, which can be remedied. Check that you are following best practice by avoiding bad sending habits that include:

  • No permission to send
    Possibly the most frequent cause for spam complaints is unsolicited mail. Avoid complaints by ensuring that you have permission to send from the start. This is usually managed by following the double opt in process when adding subscribers to your lists.

  • Recognition failed
    The recipient doesn't recognise the email or has forgotten that they subscribed to receive it. Sending an automated welcome letter soon after subscription will help establish a relationship with the recipient. Branding email templates with your website’s design and using the same “from” email address and name consistently will help to make your messages instantly recognisable.

  • It feels like stalking or you act like a stranger
    Sending email too often will annoy subscribers enough to cause them to report your messages as spam. If your emails are only sent sporadically, subscribers may forget who you are or why they initially signed up to receive messages from you. The best practice is to set proper expectations upfront and consider allowing recipients the option to choose how often they want to hear from you.

  • Messages are irrelevant
    If a subscriber opts in to receive email about one subject, don’t assume they want email about another. Ask for permission first. Stay focused and send only relevant and engaging content about the subject you originally agreed to provide information about. Use incentives to encourage subscribers to click on links that will help you to monitor engagement and interest.

  • No means no
    Once they've unsubscribed, a recipient is likely to mark future messages as spam. If your mailing list software doesn't automatically unsubscribe an address via an unsubscribe link, be diligent about processing these requests immediately. You have up to 10 days to do so according to CAN-SPAM laws, but there is no reason to stretch out the goodbye.

  • They've moved on
    Instead of unsubscribing, some people click “This is spam” to remove themselves from the list, but this usually happens because the unsubscribe process is unclear to the reader. Avoid this by making the unsubscribe link easily accessible in both the header and footer of the message.

  • Oops!
    A recipient may accidentally highlight and delete several messages at once and click on “Spam” to remove them. This is usually not a regular occurrence and will only affect you negatively if you already have a high spam complaint ratio.

Of course, on-going list management is always critical to avoid complaints. Remove old, inactive subscribers and generally avoid falling into these bad email sending habits. Unfortunately, spam complaints are a reality we all have to deal with. Luckily, ISPs and ESPs have a tolerance for spam complaints because they recognise and cater for a margin of inevitable error.

So, by simply practicing good list hygiene and email sending practices, together with regular monitoring, spam complaints can have very little effect on the deliverability of your campaigns.