Android Settings, Data usage, Three-dots overflow menu, Data usage control
The error … Connection refused … (ECONNREFUSED) means that the email server or something between the email server and the app, like a firewall, actively refused the connection.
The error … Network unreachable … means that the email server was not reachable via the current internet connection, for example because internet traffic is restricted to local traffic only.
-The error … Host is unresolved …, … Unable to resolve host … or … No address associated with hostname … means that the address of the email server could not be resolved into an IP address. This might be caused by a VPN, ad blocking or an unreachable or not properly working (local) DNS server.
+The error … Host is unresolved …, … Unable to resolve host … or … No address associated with hostname … android_getaddrinfo failed: EAI_NODATA means that the address of the email server could not be resolved into an IP address. This might be caused by a VPN, ad blocking or an unreachable or not properly working (local) DNS server. An incorrect Android private DNS network setting can cause this too.
The error … Software caused connection abort … means that the email server or something between FairEmail and the email server actively terminated an existing connection. This can for example happen when connectivity was abruptly lost. A typical example is turning on flight mode.
The errors … BYE Logging out …, … Connection reset … mean that the email server or something between the email server and the app, for example a router or a firewall (app), actively terminated an existing connection.
The error … Connection closed by peer … means that the email server actively closed the connection. This might be caused by a not updated Exchange server, see here for more information.