[Hilo] Can TCP and SMTP service work at the same time?

Answer: Yes. AT+KSMTP and AT+KPOP can work while TCP or UDP is active.
The only limitation is 8 sockets in module can be used.
And different error code (URC) would be used for different service, so no mix for them.
For example:
+KUDP_NOTIF: <session_id>, <udp_notif>
+KTCP_NOTIF: <session_id>, <tcp_notif>
+KFTP_ERROR: <session_id>,