A new version of the visual editor has been available since February 2017, namely the Mail Builder. Mailings that you create with the Mail Builder are mobile optimised. In other words, their display adapts to the device on which they are shown.
Detailed information on mobile optimisation can be found in the section Mobile optimisation – scaling and wrapping modules.
Mailings that you created with the visual editor before the Mail Builder was introduced can be recognised in the mailings overview by the 
icon. These mailings are not mobile optimised.
Note: We recommend that you recreate mailings that are not mobile optimised with the Mail Builder.
Afterwards, you can replace the mailings that are not mobile optimised in the respective workflow with your newly created mobile optimised mailings.
