blank lines in textual version of email using html mail

Hi,

First thank for your plugin, to send html emails notifications, i use

wpcf7_mail_html_header
wpcf7_mail_html_footer

But in the textual version of the email, the html header and footer create un wanted blank lines.

Can i remove this blank lines ?

Anyway i don’t understand why the html_header an html_footer are used in the generated textual version of the email, may i’ve made a mistake or misunderstood the documentation i’ve found.

thanks for your reply.