I am sending a HTML campaign for the very first time, everything works perfect with the campaign.
We have created a 'Subscribe' link, we can click the link from the HTML and are taken to the webpage, we put in name, email, age, postcode and hit subscribe but we can an error message saying the email address is invalid and to re enter the address... The email address is correct when entering.
What is the problem and how do I fix it?
The first thing to check is whether you have changed any of the form elements names - they need to be the same for the form to work.
I believe we already sorted this out via support but for anyone else who is wondering it was indeed changed form elements, just as Mathew suggested.