Email marketing is a great way to promote your business, provided you have a suitable database to work with. Your message can be precisely targeted and performance measured, so you can hone your activity over time.
I have run regular email campaigns for my clients, typically using Mailchimp but in some cases using internal CMS systems such as ACT. You’ll get a great looking html email, professionally designed and written, sent to your contacts. (The database management aspect is dependent on the systems used).