Most marketers don't have the technical facilities in-house to host their own email list once its size reaches tens of thousands of addresses. Here are some features to look for when it comes time to choose an email list-hosting provider:

• Flexible list formats available according to your needs -- announcement lists, email newsletters, discussion lists
• A robust hardware and software configuration that can handle large lists and get the messages sent out quickly
• A heavy-duty Internet connection, with plenty of bandwidth
• A system designed specifically for email marketing -- providing such features as auto-scheduled campaigns, trackable URLs and personalized messages
• A foolproof subscribe/unsubscribe system -- so you don't end up doing it manually
• Automated management of bounces and bad addresses
• Smooth integration between the list host's system and your in-house marketing database
• A flexible list management arrangement -- so you can manage your own lists via Web interface, or have the hosting company manage them for you on a turnkey basis
• Daily backups, so your valuable email lists and message archives are protected
• A strong technical support program, so any glitches get handled quickly and effectively
• Value-added services, such as marketing consultation, editorial services and copywriting
• Flexible pricing schemes, so it's affordable for you to run a small list when you're just starting out -- and so the per-message cost goes down as your list size scales up
• A well-defined "exit strategy," in case you decide to switch hosting providers sometime down the road -- make sure it's clear (and in writing) that you own your list and archive and can have a copy of them any time.

Effective list management and fast, smooth email-serving are essential components of a successful email marketing effort. Choose a reputable provider who offers a rich, flexible list hosting solution -- and who has the processing power and bandwidth to scale upwards as your lists grow.