If you are looking for work in London, you've to remember so are millions of others, it is a VERY competetive employment market and when it comes to journalism and that kind of thing, you can mulitply that by 100. An email isn't going to get you anywhere because HR departments and recruiters probably get bomarded with hundreds of them. Luckynicky, as you have already found out, you get a better response if you telephone but on the whole you are better off applying for jobs that have already been advertised, or following up through an already established contact.