I already mentioned the delay should be considered only if you can't immediately send another message from pfnMessageEnd. Either use a small task, a thinking entity that would allow you to think faster than 0.1 seconds or if you are using amxx 1.9+ look into http://amxmodx.org/api/amxmodx/RequestFrame
I repeat, test without any kind of delays. If the server crashes then consider adding a delay.
Problem solved it worked there was no need for a delay since the message_end & message_begin were blocked.