Already many years ago I remember installing a firewall on my phone and noticing in surprise that Outlook was not connecting at all to my private mail server, but instead only sending my credentials to their cloud and downloading messages from there.
The only Android mail client not making random calls to cloud servers was (back then) K-9 Mail.
Already many years ago I remember installing a firewall on my phone and noticing in surprise that Outlook was not connecting at all to my private mail server, but instead only sending my credentials to their cloud and downloading messages from there.
The only Android mail client not making random calls to cloud servers was (back then) K-9 Mail.