ESPs understandably care very much sending quality marketing content, and limiting the number of emails uploaded helps regulate how your new subscribers are responding to the content you begin to send them.
When you upload a very large list into your ESP, your ESP may may not be able to differentiate a large list from a sweepstakes (a legal way to obtain emails from people who explicitly agree to receive marketing communications from you) from you a purchased list of email addresses that have not opted into receiving communications from you. This can set off spam warnings and harm your ESP deliverability.
While we know it can take longer to upload shorter batches of emails, it's important to us to help you avoid any deliverability issues with your ESP.
To save time in the future, we strongly recommend integrating with your ESP, which will send entries directly to your email list.
- Integrating means a higher performing list - List quality is much higher when you reach people right away. Even 2-3 days can make a big difference in performance- the longer you wait to reach people, the higher the unsubscribe rate and the lower the open and click through rates.
- It saves you time - Integrating sends entries directly to your list, which can then trigger marketing immediately - no more downloads, uploads and sends.