You should start providing value to your immediate network and share your knowledge to start establishing your "brand".

Here are a few practical ways to do so:

1) Set up a Clarity.fm account in your areas of strength.
2) Write key ideas and lessons you've seen are needed by your potential customers, and publish them as a blog post within your Linked In profile.
3) Attend key conferences in the area of email marketing, and engage and connect with other experts in your field. There is always something new you can learn, and you'll potentially discover opportunities to add value for others.
4) Publish your own blog under your own domain. This is a long play, and is definitely valuable when you go interview for a job, or when you're trying to land a speaking gig.
5) Write an eBook on your favorite email marketing related topic, and offer it over your LinkedIn profile or personal blog.
6) Reach out to your local business development office -- many times they are in need of local experts and can offer you first-step opportunities to start getting your name out as an expert.

If you think about it some more, you can probably come up with other ways. There isn't a silver bullet or easy way up -- most of the times, you're going to have to hustle and make long term investments one step at a time.

Best of luck!