I am getting spurious messages that some of my messages have been blocked because they are "spam" or...

I am getting spurious messages that some of my messages have been blocked because they are "spam" or at least you think they are. Firstly, in some cases at least they aren't actually blocked - they are delivered to the recipient. So that information is false. Gmail wasted my time and furthermore, I can get no information as to what is causing this (they were two photos). Secondly, what gives the right of Gmail or Google to define spam on my outgoing data and then blocking it? As far as I can see Gmail operate a messaging service. If I wanted Gmail to examine my outgoing messages to see if they are spam, it should be a service I can elect to have. For me, I do not want Gmail interfering with my messages based on an algorithm and puitting me to endless trouble and confusion. Lastly, it does not appear any of these issues are fixable by me - I have no tools to stop this happening. At least please give me back my own control over my outgoing data. Thanks, johnM