Some companies send out email messages to new or existing client bases in order to notify them of current news, events, special offers or new products added to their range. This can be a great way to drum up extra business and many companies have great success in marketing this way.
There are many options when it comes to email marketing. You can crate and send the email yourself but you should be aware of limitations in sending from your server that hosts your emails as some do not allow over a certain amount of emails to be sent in one period or may even cause your server IP address to get blocked and therefore not allow the emails to be delivered to the recipients.
The best option is to use a company that specialises in email marketing as they will have the correct servers set up to handle the volume of emails you wish to send. Some software allows you to create the email with a drag and drop feature, where others will require you to upload HTML code for the email. If you need the code version of the site then you can either ask a web developer to create this for you or see if the email marketing company has an in house department that can create it for you based on a visual.