I try to keep this lottery syndicate as informal and friendly as I can, however, I need to keep track of who paid what and when, and I need records of a standard that will hold up in court when we're arguing over hundreds of thousands of pounds. Ideally you should pay me in person, at my desk. I will sign your receipt while you watch, that is your legal record. Sometimes I'm not at my desk when you want make a payment, when that happens you can leave a payment with one of my colleagues, preferably Helen, and you must email me to tell me how much you left and when. If the timestamp on your email, and Helen's account match, then I'll happily accept that you made your payment before the draw.
Yes, someone could conceivably notice that their number has come up when they're not paid up, and then persuade Helen to presenting the payment as though it was made before the draw, and convince Rich I to turn back time on the email system while they sent me a notification email, but it's not a risk I'm prepared to guard against.
Richard "dictator" B