If you plan to develop an email newsletter by sending mass emails, testing is required to ensure that no problems exist. Many tools that are found online allow you to perform a test on your messages to see if they will be displayed correctly on different email clients. You can easily do this online by using for example Email on Acid.
The tools or services that are used to test your email should absolutely perform a spam filter test. This is a type of analysis to see if the email is getting caught by email spam blockers, Litmus' email testing tool for example offers this kind of feature. Such an analysis will check the email content and the server that is sending the message. When selecting an email spam tool, make sure that it tests your email for the spam filters of all majors email clients like Outlook, Gmail, Yahoo and others.
Preview of Code
The code used for a message is used to generate an email preview that you can use to view the result of your HTML on your display. Various types of diagnostic tools are used to compare the results. This is a type of simulation that can be used to ensure that the rendering of your HTML is correct in each type of email client. Simulations are done to match the rendering in a web browser.
Analysis of Code
The use of an email testing tool provides you with an analysis of incorrect code. HTML code for an email that does not render correctly or is incompatible with an email client will be highlighted. This allows your email to be examined for errors and issues that may exist in the HTML code of the email.
Validation and Optimization
Tools that are used to check your email may provide HTML validation. A test with Email on Acid will help you determine if the code that is used for a message is W3C compliant. Validation is important when a web-based email client is used, as a misplaced tag can cause a misconfiguration with the desired layout. Proper design of an email message is important for rendering in a browser or third-party email client.
Blocking of Images
Many email clients have built-in image blocking to increase load times and decrease spam. This needs to be kept in mind when testing emails in different email clients. You will want to tailor your messages to ensure they are readable without images being loaded. The trick is to make text on images appear as text using the picture simply as a background for the text. Also, make sure to enter alt=”” tags for your images in case crucial images wouldn’t show up in certain email clients.