PIN email not being sent consistently - not in spam, not in server logs


I’ve got a user who isn’t receiving PINs, or they are so delayed that they are expired when they arrive. After checking with their email host, they received this response:

*"I checked again all the logs and the spam filter. The only thing I can see are those 3 emails that we looked up last time. As you can see they show as delivered normally, this means that the sender is Trusted. *

We didn’t find anything in the logs that means that the email did not make it to our infrastructure at all. So, they probably didn’t send any email yet."

My app’s URL:

Which is it?

The normal deliveries are either referring to ones made months ago, or to the few attempts that did generate a PIN but were so delayed that the pin was expired. Their most recent attempts (Friday, that I know of) aren’t showing up at all.