Mass email vendors typically fit into one of three common service offerings — ASPs, software providers, or full service firms. Each option has its advantages and disadvantages — it's important to choose the type of provider that best suits your needs and budget.

ASPs
Application service providers (ASPs) offer mass email services through a subscription model. They host the email software on their servers and send your messages using their bandwidth and infrastructure. You pay monthly fees based on the number of email addresses on your list or the total number of emails you send. ASPs are primarily self-service solutions, allowing you to log in, upload your names, and load your content into templates. The vendor's system manages the names and addresses and sends out the mass emails.

The ASP model is best for small businesses because it's easy to get started and inexpensive. Vendors provide customer service by phone or email to work out any problems. You also benefit from working with vendors with a lot of mass email experience.

As with any ASP, you're dependent on the vendor's uptime and ability to deliver. If their server goes down, you may not be able to get emails out. Also, some ASPs may only offer limited list segmentation capabilities. Most importantly, if the vendor's domain has been blacklisted by ISPs in the past, your emails may never reach part of your list. Be sure to ask any ASP vendor you are considering how they prevent their network from becoming blacklisted.

Software providers
Purchasing a software solution for mass email requires that your in-house staff install the software on your own servers, manage the software, train employees, and address any problems that come up. You don't have to worry about previous blacklisting complaints, and you get complete control over the setup and maintenance of the system. Also, there are no month-to-month fees so you can amortize the cost of the software over three to five years.

However, in-house software can be an expensive option requiring a large up-front investment for the hardware, necessary bandwidth, licensing fees, and staff to manage the software. It puts heavy demand on your staff's time to maintain a clean reputation and to send mass emails. You also need to establish relationships with major ISPs if you run into delivery problems with your campaigns. Finally, it requires that your company stay on top of changing email laws.

Full-service firms
If you want an agency that will handle your entire mass email campaign from start to finish, a full-service vendor is the way to go. Full-service firms have a lot of experience working with clients in different industries, avoiding blacklist status, and creating valuable content for email promotion. They will also help format emails and perform small test mailings before a full campaign. Full-service firms typically offer the most advanced personalization, segmentation, and targeting capabilities of the three types of providers.

This extra level of service doesn't come cheap — expect to pay several thousands dollars per month. It's probably not an option for many small businesses.