I can't receive e-mail

Used in Japan.

The OS is Android13.
I haven’t been able to receive E-mails lately.

Even after uninstalling the App and installing it again, the problem remains.

The incoming and outgoing mail server settings are correct, and the network background synchronization has been changed to “Always On”, but the problem remains the same.

After installing another E-mail software,
I am able to receive E-mails properly.

Is there any workaround?

Best Regards.