This is a limitation on Google's side, a Gmail account allows up to 15 simultaneous connections / logins per account -- ***counting all mail apps on all devices, mobile and desktop, excluding Google's own Gmail app, of course***
About what Aqua needs: one connection per folder set to "push" + one connection per account for scheduled mail checks.
Please see the FAQ for more details, it's at the end:
http://www.aqua-mail.com/?page_id=227Possible causes:
- Too many folders in push mode
- Frequent connection loss
- Other mail apps that try to use push moder for every folder in the account, eating up the limit (since Gmail counts all apps on all devices).