Email Delivery

What is spam? How is your email marked as spam?

Spamming is a real plague to all bulk emailing senders. Read this article to learn more about spam and avoid spam issues.

According to Cisco's SenderBase, in 2016, more than 85% of emails sent are spams (source), so anti-spam filters are becoming more and more aggressive. When you are sending big mass emailing campaigns on a regular basis, at some point you will be very likely to face spam issues. Even if you are an honest email marketer, chances are high that some of your emails will fall into your recipients' spam folder (and thus never reach their inbox).

While it would be unrealistic to avoid spam filters in 100% cases, it is yet possible to reduce the number of emails flagged as spam.

The most common example is the salesperson who purchases a list of email addresses online (from an external data company) that contains leads for his business. The commercial starts to email them with a targeted and relevant message, hoping that they will become prospects then clients.

Why does this example reflect a bad emailing behavior? Because the recipients from the list have never accepted to receive emails from the salesperson. As they didn't give their permission (e.g.: By subscribing to the emails), Google (or other webmail providers) will consider this activity as suspect. In the end, this can be harmful to your account / domain reputation.

So next time you are trying to send another campaign from your Gmail or G Suite account, your emails might be flagged as spam. If this is repeated (specifically for newly created accounts which have no reputation), Google might block your account.

Spam laws depend on each country. We invite you to check the current spam law enforcements in your own country. 

In general, you should apply the two key rules:

• Never use deceptive reply-to addresses, subject lines or names
• Always include a valid unsubscribe link to your emails

Several criteria are considered by spam filters to evaluate the 'spamminess' of your emails. Among them:

• Your email header (or metadata): These metadata include the Date:, From:, To:, and Subject: of your email. Spam filters will check if your recipients already know you. That's why you should use a verified domain to send your mail merge, personalize the subject line, and ask for their permission to send them emails
• Your IP address: If you have spammed people in the past, spam filters will remember your IP address, and flag futur campaigns from this same IP address as spam.
• The HTML code of your email: Unstructured HTML code will be suspect to spam filters. Sloppy code can be imported from Word or Google Docs, so we always recommend to create your draft directly in Gmail, or use one of our pre-designed template.
• Your email content and formatting: Although there are no strict guidelines for the formatting, the combination of some specific words, colors (red / aggressive colors), typographie (capital letters, abusive use of exclamation marks) etc. in your email might be considered as spam. Your email content should be clear and consistent with the subject line / audience. There is no miracle, so the right thing to do is always to test different emails.

It's very easy to flag an email as spam: When people receive unsolicited emails, they can simply click on a button and report the email:

Now that you know what spam is, and how your emails can be flagged as spam, please read our article about best practices to avoid spam filters and reduce abuse report.