I'm working on an "invite a friend" feature and would like to send emails in which the "from" field is the email address of the user sending the invites.
I saw that evernote's emails are sent like that, and gmail shows some text saying "via evernote.com".
I'm wondering what's the correct way to do something like that and not get hit by spam filters. We're currently using postmark as the service through which we send our emails.