Hi!
If my phone changes connectivity while accessing the servers r2mail does not handle this situation very gracefully. Sometimes it gets completely stuck complaining about unreachable/inaccessible servers until shut down and restarted. Or today I had a warning that the folder is opened in read only mode.
This happens mostly if mobile data is active and the phone changes to WLAN or back to mobile data while r2mail accesses the servers.
For the usual workflow... unlocking the phone, opening r2mail, "get mail" ... I often reach exactly the point when WLAN gets connected (since I'm using GreenPower as a Juice Defender replacement), On larger WLANs like eduroam you often get disconnected to "convince" your device to move to another AP or frequency as well.
Greetings,
Wolfgang