With Trading Players, you can safely trade your items with other players.
Use "/trade send [player]" to send a trading request to [player]. Once you received a request, you can accept "/trade accept" or refuse "/trade refuse".
The two players must accept before the trade is processed. If a player leaves the trade, it's cancelled and the players get their items back.
The mod must be installed on client and server forge mods folder.
GitHub available !