Hi,
1 - Please check app settings -> Mail, receiving.
Some phones (my Huawei Honor) may "remove" the app from "Doze Mode exception" after a few days.
If the app needs to be excluded again, there will be a green panel / prompt on that screen.
In addition, "scheduled mail checks" should be enabled.
2 - There are phone manufacturers that pre-install their own "battery optimizer" on their devices.
Some examples: Xiaomi, Huawei, ASUS.
Perhaps your phone has one of those "battery optimizers" built in too, and if it does (best check with the manufacturer's support), please white-list the app there too.
3 - Swiping the app away from "recents" ("running") apps can, on some phones, also prevent scheduled mail checks.
4 - Your phone's "background data" should be enabled (if not, the app won't be able to access the network, which it needs to check mail).
5 - A "third party" battery optimizer app such as Clean Master also can prevent Aqua Mail from checking mail (making it impossible for the app to work in the background).
If you still have problems, please email us at support @ aqua-mail . com to have your issue resolved.
Thank you,
Nadia