Diaspora/Diaspora

where this string is used?

As link text on the right side of the stream pages. It's interpolated into aspects.index.help.email_feedback

So it is used here, and it is a verb, right?
"Email your feedback, if you prefer".

Yes, but nothing holds you from rephrasing it to "If you prefer use E-Mail to give us feedback" or to shift the mailto: link to a whole other place in the sentence as you can freely edit the link text and the place it's interpolated. Whatever fits best in your language.

Ok, thank you