When viewing an email campaign on a mobile such as an iPhone etc you may see that the first line of text is shown as a preview to what the email contains. 

If what you see if the text: 'Having trouble viewing this email?' then this is due to you having put the 'view online' link at the top of your email campaign as shown in the example below: 

To resolve this you can either: 


1. Insert the view online link elsewhere on your email template – which would mean just removing the link at the top of the campaign and inserting it at the bottom of the email (above the Unsubscribe link).


2. Alternatively you could remove the ‘View Online’ link if you have no images for the recipient to download.  The View Online link is there in case the images on the email are blocked by the recipients email client.