FileTranfer service-unavailable(503)

When target user is online at that time file tansfered successfully.

but when target user is offline at that time it throws “service-unavailable(503)” exeption.

can we send file like message?.

When taget user come online at that time he recieved file?

The closest thing there is is XEP-0066: Out of Band Data (jabber:x:oob). But Smack does not support it.

You would also have to upload the file somewhere on a file server first. Then send the message with the URL to the file.