I think this requires sending multi-packet or multi-part messages or something like that as I believe newer protocols support. I think the limit per message-part is 5 emoticons and hence by sending a multi-part message, the limit can be increased. A similar method could also be used to send very long messages (as the character limit only applied to each message-part) although I'm not sure if this has been altered as it was possible to cause a buffer overflow by sending infinitely long messages.
PS: I may be completely wrong about all of this but I do remember reading about it or something similar
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