How to write to producers as an actor
With regards to actors/actresses writing to producers I used to do it a fair bit and it sometimes got ignored, but on the rare occasion I got a reply, a casting and then the job. But be careful, especially young women. Some producers will try their luck and may even try to take advantage. Just do your research first! Ask fellow actors about this producer, directors you have worked with and if they know of them or have worked for them, camera crew, anyone, just ask around. Chatting with fellow actors is a good step, check on CCP or IMDB for their film credits and see if you know anyone in their films, ask about their experience, how they met etc.
Also, speak to you agent. Agents are fountains of knowledge.
So, once the research is done, I think in the UK especially when there on so many levels of film making its ok for actors to write to producers, just don't harass them. But be honest, dont lie about your credits or your work, if you were a supporting role, say it, dont big it up to be something it isn't, as people will always find out and will probably be quite irritated.
In the US its a different story, most producers have managers which you would need to go through, and therefore prove almost impossible to get anything from all that effort.
But in the UK I think it is worth it, just be smart and on your guard especially in the lower end of British film making. If a producer gets you in front of the casting director that's a great contact to stay in touch with. But they cannot guarantee you the job. Even if you end up being business buddies, there are still alot of factors in place that means you may not be right for the job, getting the role is a joint decision, the producer and director must love you and sometimes so does the investor. Its tricky.
But as long as you have your wits about you... go for it. It cant do you any harm.