Core/Guilds: Fixed "Guild Mail" perk.

src/server/game/Handlers/MailHandler.cpp

@@ -337,6 +337,11 @@ void WorldSession::HandleSendMail(WorldPacket& recvData)
     // If theres is an item, there is a one hour delivery delay if sent to another account's character.
     uint32 deliver_delay = needItemDelay ? sWorld->getIntConfig(CONFIG_MAIL_DELIVERY_DELAY) : 0;
 
+    // Mail sent between guild members arrives instantly if they have the guild perk "Guild Mail"
+    if (Guild* guild = player->GetGuild())
+        if (guild->GetLevel() >= 17 && guild->IsMember(receiverGuid))
+            delivery_delay = 0;
+
     // will delete item or place to receiver mail list
     draft
         .AddMoney(money)