XF 2.1 How to set up emailing so bounced emails change user state to "Email invalid (bounced)"

[Feanor]

I have the default email transport method set, but I would like XF to recognize when emails are not being sent. If I understand correctly, I need to change from Default to SMTP*. I know some forums use SMTP to send emails from a third party, but can I continue sending them from my server? Do I just have to fill in SMTP details from my own server and it will start putting users with invalid emails into the invalid / bounced state?

*Edit: I'm not sure here either because it says "Note that this option may not work unless the return path parameter is enabled or mail is sent via SMTP using the Email Transport option." So if I'm reading this right, it can stay as default if I put the email information where the bounces get returned to under "Automated bounced email handler?"

Edit2: Now I see it says this email "MUST be directed to an account whose sole purpose is collecting bounce emails from this XenForo installation." If I am understanding correctly, what I said in the first edit isn't exactly right and I would need to have my server forward just the bounces to a specific inbox to put here? Would XF parse the bounced email address from Mailer-daemon's email?

 

[DigNap15]

And once the member is changed to the Secondary User Group "Email Invalid"
What would happen then?
What does XF do

 

[Rhody]

And once the member is changed to the Secondary User Group "Email Invalid"
What would happen then?
What does XF do

When I manually (or automatically) set their "USER STATE" field to "Email Invalid (bounced)", this is what a member on one of my forums would see:



I did modify the default PHRASE and put the text in larger red, with some changed words, but you get the idea. When they fix it, they will be validated by the system, and their access will be restored.