There are two types of formats of email: HTML or simple text.
MailPoet sends both versions, but you only see the colorful HTML version. Some email clients, such as some Blackberries, only show the text version. Otherwise, it’s hidden from you, unless you see the source or original email.
Spam filters also like to see a text version with the HTML email. Spammers often don’t bother creating a plain text version.
How to view the plain text version? Each email client as a menu for that. We won’t list them here, but a quick search in the Help menu of your email clientor in Google will do.
For example, in Gmail, you can find it like this: