I think At least there should be something in the user account that says eg "No spam!" or other warnings. I know how sensitive this issue is and I will not overwhelm this forum with spam because it will have a negative impact on me and my business. I am just trying to find balance.
If I send PM manually and each is unique in the sense that the message is addressed to a specific person and says there is content related to this person's activity or interest, it should not be treated as spam. Feedback is generally positive and some people log onto our platform. This means that my information has value to them. I am not asking to join the platform but for opinions on business models, websites etc. So as long as no one complained and reported me it was Ok.