Is there any way to know how many of our messages are sent to spam folders rather than the general inbox? Is that part of the soft bounces?
Spam ratings are measured by "spam complaints" which are different than the message going directly to spam. Spam complaints means that the user specifically clicks "report spam" on one of your messages. When messages are sent directly to spam, we don't receive any sort of reply for that, so we can't track it. If the recipient email server interprets one of our messages as spam for any reason, then it might decide to reject the message and that will send a bounce reply to us since it never made it to the user's inbox. In summary, it is not possible for us to track messages that were sent to the recipients spam folder because it was accepted by the incoming mail server and no reply is given back to us to suggest otherwise.