This tool focuses on the possibilities of sending emails via SMPT or email API as an integration into various applications or automation solutions (e.g., the Emailit node in Ottokit: enter API key, use, no major effort required).

EMailit positions itself as a flexible basis for sending emails (from european mail servers), not for creating or managing newsletters - if that's what you're looking for, you should use a different tool such as MailWizz: once you understand how to complete the configuration there, you will also understand the added value of EMailIt.

Otherwise, it would be a good idea for EMailit to be supported directly via an API connection at fluentsmtp - for those who find the configuration as SMTP too complicated. This is a simple option of resending emails that somehow didn't quite work... at least in the WordPress world :) For your own applications, you'll have to put in more effort yourself until the Resend-feature will be perhaps available in the EMailIt backend.