Michael Heering

Deliverability: better email delivery with Copernica

Written by Michael Heering Borja Sanz on

When creating your email campaigns you want to be sure of a good deliverability. Copernica Marketing Software offers different methods and tools to improve your

Split-run testing

Relevant emails generate more response and less requests to unsubscribe. That is why it's important to know which content, lay-out and presentation form of email your target group responds to best. To find out, you can test emailings by using a split run (A|B) test. It allows you to send different versions of your emailing to a limited selection of your target group. The most successful version of your emailing will then be sent to the rest of the database.

By optimally adjusting emailings to your target group, you can achieve a higher deliverability and response rate. Copernica offers split-run functionality, from creating selections to deciding the winner and sending the final message, in one easy-access function.

Litmus preview tool

Contacts' inboxes are usually spread over many email clients, each of which has its own influence on how your email is displayed. Yet you want your email to look the same for each recipient, the way you sent it off. Litmus is a tool which can make snapshot previews of your emailing in a wide variety of inboxes. It allows you to check if your layout will be displayed as you want it. It even lets you see the message with images and links enabled and disabled for each inbox. Previews are rendered from, among others:

  • Yahoo! mail (3.0, 2.0)
  • Gmail (firefox/explorer)
  • Hotmail (firefox/explorer)
  • Outlook (2000, 2002 XP, 2003, 2007, 2010 beta)
  • Windows Live Mail
  • Apple Mail

The Litmus tool is integrated into Copernica with an easy one-click function. Using Litmus allows you to optimize your emailing for each mail server which in time, improves your deliverability.

HTML check

The source code of your HTML-documents which are sent out as e-mail should always comply with the international standards. Errors in HTML code lead to incorrect display of your email, error messages and possible misjudgement of your email by the receiving mail server.

Copernica Marketing Software offers a built-in HTML check to track down possible errors in the source code before even sending an email.

SPAM & blacklist check

When your email is ready to send, you can perform a final spam sensitivity check through our software. It calculates how easily spam filters will let your message through to the inbox. Any issues that will negatively influence those chances are reported back. An important aid when optimizing your deliverability.

Furthermore, the Copernica mail servers continuously check if they are suspected of being spam senders. To do so, they are connected to a number of organisations that watch over e-mail traffic through blacklists (Return Path, Lashback, Listbox, and others).

Improving email reputation

Your email reputation is an important factor in the deliverability of your e-mail messages to the receiving mail servers. Two situations can occur when sending an email:

  • The email is delivered successfully
  • The email is stopped because, for example:
    • The mailbox no longer exists
    • The email is considered spam

How often these situations occur, determines your email reputation as a mail server. If too many e-mails are blocked, it will harm your reputation and deliverability. As a consequence, future emails will be blocked and labelled as spam automatically.

To prevent a bad email reputation, Copernica helps you to:

  • Schedulde emailings to be sent at predetermined moments
  • Accurately monitor your email statistics
  • Repair and remove faulty email addresses
  • Personalize emailings for target groups and individual recipients
  • Automatically opt-out users who report your email as abuse to the mail servers


Aside from the steps you can undertake within our software to positively influence your email reputation, you can also apply for certification. There are several organizations which monitor the reputation on mail servers closely. Return Path is amongst the best known and most reputable of these organizations. With the services of Return Path you can track the state of your email reputation.

You can apply to become a Return Path Certified Sender through Copernica. To do so, you need to comply to the rules and after a positive review from Return Path, you will be certified. Return Path Sender Certification places you on several reputable whitelists. It also grants you privileges such as instantly displaying your images in Hotmail and Yahoo and direct activation of the hyperlinks in your emails for those browsers.

List-unsubscribe header

Another function that will lower the spam sensitivity of your emails is using a list-unsubscribe header when sending emailings. This allows the recipient to unsubscribe from your emails through the header information rather than clicking inside your email.

The list-unsubscribe header sends along extra data with your email. That information is transformed into an unsubscribe button by the email client and it is also directly linked to your marketing software. A click on the hyperlink will automatically be picked up by the Copernica software and trigger an unsubscribe or deletion of the contact (as you wish).

Including a list-unsubscribe header will improve your email reputation and deliverability because it keeps contacts from hitting the spam button instead, and because spam filters award credit to sending this header along.

Authentication techniques

Authentication is checked by default by receiving mail servers on every incoming email. Spam senders typically use false sender data and are therefore filtered this way, which is why you need to be able to prove your identity and authenticity on the doorstep. Invalid authentication data will have a bad affect on the deliverability of your emailings. Using Copernica you can create and double check the following data: