String at the top of each response email

Hi Mihai,

I have an issue with the response mail send via MC4WP plugin.
The value for the hidden field which is inject by your plugin is also included in that email. Is there a way to exclude this string?

tq0J8KxYRUHgAlEelN3EpTgeNzT7-awEaVdlNoAlYicgQPKDLgSEAJqJAG03p9SgRulnZEQDertcMRMgcwrgN-nhpINVi1waJnyZFjcWsdtOkHaTbOlhsA

First I thought this is a question for Danny, but the asked me to contact you:
https://www.ads-software.com/support/topic/strange-string-at-the-top-of-each-auto-responder-email/#post-12523281

Thanks