I send transactional emails from my application on my customers behalf. I'd like for the receiver to be able to click reply and have the reply go directly to my customer, without ever touching my server.
If I send an email from me@myapp.com with the reply-to header set to customer@gmail.com will my transactional emails be flagged as spam? Is this even the slightest red flag to spam filters? It's important my emails don't get caught in the spam folder and i've spent quite a bit of time ensuring that my email is sent properly so I just want to be sure before I implement something like that. Or is this a fairly common practice that I shouldn't be concerned at all about?