Section in the mailing that can be changed

Content

I have a requirement that one small portion of a mailing should be dynamically editable.

For example, my mailing remains the same throughout but one block of code changes.

I need not change the whole html of the mailing, that dynamic content should be changed in the mailing.

I was going through snippets, but after they are added to the mailing, even if they are changed, the change would not reflect in the mailing content. I want it to reflect in the mailing.

Version

May 2015