We created our email and LP templates outside of Marketo and included our responsive CSS in order to do so. Once we added it to Marketo and added the <div> tags for editable areas we saw some of our code wiped out and the responsive nature ruined.
Have any of you experienced this? How did you mitigate the issue?
Could you include a snippet copy of your code and the email/LP in question? Marketo does strip code, but usually only if it finds something that's broken (as I have painfully learned through many bad copy/paste incidents ) My guess is that there's a stray or missing character somewhere and Marketo is removing it as it sees it as invalid. Otherwise there should be no problem using responsive scripting in emails/LPs.
If you are creating a new "Guided" landing page template, nothing will be stripped. I can look into it if you give a specific example. Are you sure it's happening in both LPs and Emails?
Yes, it's all custom code we built outside of Marketo and then placed into the templates. Lejf Hansen could it be an extra character in our code?