Theoretically, there's no maximum number of recipients you can have in your MailChimp lists. However, MailChimp's a browser-based application, so there are a few things you should consider when you have a large list.
- Importing a very large list into MailChimp can take a while. If you're seeing this take an extremely long time, reach out to a developer to look into syncing your database with MailChimp through the API.
- If you import a list of more than a few hundred thousand subscribers into MailChimp, keep in mind that some list pages, especially list statistics, will load slowly.
- If you try to perform a search across a list of hundreds of thousands of subscribers, it could be slow or unavailable depending on your list size.
- MailChimp can theoretically send millions of emails from our servers per hour, but no internet service provider (ISP) would actually accept that much email so quickly. ISPs throttle emails to prevent massive spam attacks from bringing down their services. To work toward better delivery rates, we in turn throttle our delivery, based on each ISP. This results in slightly longer delivery times for very large lists, but overall higher delivery rates.
If you think you are eligible for the High-Volume Plan, contact our High-Volume Team here.