问题
When I write messages to a user who is offline - without sending it - I get an error
Your message was not send because of an error
pick error
response:
/http-bind/<body xmlns='http://jabber.org/protocol/httpbind'><message xml:lang='en' to='abogdanov@bingo-dev.ru/181473147433257603378' from='jabberadmin@bingo-dev.ru' type='error' xmlns='jabber:client'><paused xmlns='http://jabber.org/protocol/chatstates'/><error code='503' type='cancel'><service-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/><text xml:lang='en' xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>User session not found</text></error></message></body>
回答1:
Your client is trying to send "typing notifications" to indicate user you are typing, and doesn't handle errors well: it should not show errors for typing notifications (or not send it to offline at all?). Also, you may have disabled offline storage at your server and that is why server report errors.
来源：https://stackoverflow.com/questions/43979472/user-session-not-found-error-code-503