I discovered a very minor "feature": The phone is connected to Wi-Fi, but the connectivity is absent (it requires authentication via browser, and lost the previous one). In Aquamail, while viewing a message, I choose "view" -> "headers". Aquamail shows that it's working, and then nothing happens. I.e. there is no message that it cannot connect to the server or anything else.
I would expect it to produce some error message, informing while it hasn't displayed the headers.