【进阶实战】跨服邮寄：跨服邮件的延迟投递封装

local function sendCrossMail(actorName, homeSrv, title, rewards)
    local mailId = "XM" .. os.time() .. math.random(100, 999)
    local receipt = { id = mailId, home = homeSrv, to = actorName,
        title = title, rewards = rewards, ts = os.time() }
    routeToServer(homeSrv, receipt)
    return mailId
end
local function onCrossMailArrive(receipt)
    sendmail("#" .. receipt.to, 0, receipt.title,
        "跨服奖励投递，可能延迟数分钟。", receipt.rewards)
    sendmsg(getplayerbyname(receipt.to), 1,
        "跨服邮件已送达：" .. receipt.title)
end

local function queryCrossMail(mailId)
    local st = getsysvar("CrossMail_" .. mailId)
    if st == "" or st == nil then
        return "投递中"
    end
    return st
end