arent checked customer email filter issue listed log page purchase receive receiving resent settings spam transaction troubleshooting

Hi there, I have a customer who says they didn't receive their email. They are listed on the transaction log.
I resent the purchase email and they say they still aren't receiving it. Any idea what could be going on?

If you have checked the troubleshooting page and there is nothing wrong with your settings, then it seems like an issue with their spam filter.