Tesco Mobile and the misdated emails

I'd noticed once or twice before that my email system (Thunderbird) would flash up a "new email" window to alert me to a Tesco Mobile email (notification of bill) but that when I went to my inbox, it wasn't to be found. I could find it using a search, but I was beginning to get worried about the integrity of Thunderbird.

But now I have sussed it: it was Tesco at fault. They send their notifications with the Date field set 24 hours too early. Result: if you have a reasonably crowded inbox, it disappears "below the fold" and you will not see it unless you go looking for it.

I have no reason to suspect that this is a deliberate move by Tesco - most likely pure cockup caused by an erroneous adjustment setting to allow for the fact that they are sending the emails from Australia (why?) - but it does happen to be a particularly profitable outcome for Tesco: users paying with Direct Debit who don't see the email don't get to spot how much they are spending with them which might otherwise prompt them to cut back usage or consider a cheaper deal.

I've alerted Tesco, and will update this if I ever get a response.