The preheader is a short text that is displayed underneath the email subject in the inbox, before the email is opened.
The text is only visible in the inbox, and not once the email has been opened. This is what it looks like in Gmail:
Find out here which email programs and providers display the preheader:
Provider | Preheader displayed? | Correct display in Newsletter? |
web.de | No | Yes |
gmx.de | No | Yes |
gmail.com | Yes | Yes |
yahoo.de | Yes | Yes |
aol.de | No | Yes |
freenet.de | No | Yes |
outlook.com | No | Yes |
t-online.de | Yes | Yes |
thunderbird | No | Yes |
Android | Yes | Yes |
iOS | Yes | Yes |
Outlook | Yes | Yes |
Read this help article to find out how to use the preheader.