Over on the E-Consultancy blog, Dela Quist offers some excellent tips to help you find the right email service provider:

• Go for the larger companies. Their servers are going to be more robust, they’re likely to have more staff, including a big ISP relations or reputation management team and have the ear of companies such as AOL, Microsoft and Yahoo!.
• In particular, ask how many people they have working on ISP relations and reputation management. Ask whether their reporting can give you a breakdown by domain so you can see which ISPs are causing you problems.
• For those that prefer it, there are some very good European ESPs to choose from, but don’t be afraid to work with an American company as they dominate the email delivery space. This truly is a global business and experienced companies of scale are often US-based.
• Establish how familiar they are with your needs. It makes sense to try to find out what percentage of their clients are of a similar industry, size and have similar needs to you. You can then select the provider with the most clients matching your scale and requirements.
• Don’t be seduced by functionality.Focus on the functionality you need now or in the very near future. What you’re really looking for is ease of use and interface speed. The delivery service you choose should have a user-friendly, intuitive interface that makes setting up and automating repetitive tasks straightforward.
• Support is also very important, particularly if you’re going for a self-service solution. So ask how quickly they turn around queries, whether they offer telephone support or just email.
• Email marketing is all about understanding how your customers are interacting with your communications. So the reporting interface is absolutely critical and there are significant differences between products. For example, not all technologies allow you to group your mailings by campaign. In some ways, it’s more important to look at the reporting interface than at deployment functionality. Good email marketing is a constant learning and feedback loop, which requires detailed reports.

Source: E-Consultancy.com