Yeah, pretty much that. with my own gmail account or Because a client reported back.
Discussion
i have to test this for my mailserver at some point. maybe i am lucky cause the ip is pretty old at this point or i just don't know that my emails land in the spam folder. i get at least some answers to my emails, but maybe that person looked into the spam folder, never asked...
Some providers are stricter than others. Gmail is kind of the worst deal with, They have extra criteria that can land you in the spam folder, even if your email server is up to snuff. Yahoo and Microsoft seem to be a bit more lax.