Do you always have to manually subscribe to the threads you post on, or is there a setting somewhere?
Or is it just not working for me?

I have found that if I don't manually subscribe to a post then I don't get email updates about the post... is this normal?

Never did get an answer but still looking for one

To answer the question, threads are not auto-subscribed to by default. In addition, there is no such setting to auto-subscribe, at least to my knowledge.

I believe this is intentional so as to limit potential unwanted emails, erring on the side of caution regarding that the user may not want so many emails. Also, if you added the functionality to auto-subscribe on post, then you'll always be needing to click 'unsubscribe to thread' on those ones you don't want a subscription to after posting.

Personally i just like to be able to know when someone has responded to something I have posted...

...the Butterfly is correct. Subscription to threads isn't automatic for the exact rationale she provided... you don't really want to be updated everytime someone updates one of the Posting Games threads that you only participate in 'every now and again,' do you? You do likely want to know everytime someone has updated a rules based game that you're participating in regularly, though... and, if you happen to stop playing in said game (because your character died or RL kidnapped you or whatever) you can unsubscribe if you don't feel you'll be keeping up with it any longer.

We like to give you some choices.