In this case my client had subscribed to a third party website newsletter. It was a UK Government website, so one might reasonably suppose they know what they are doing. …. which turned out not to be the case.
The newsletter which was sent out quite frequently included lots of links in it to other websites. It also showed the sending domain in the message, let’s say in this case it was finance.gov.uk. So the incoming messages appear to come from the domain https://finance.gov.uk. However they were going into the recipients junk email folder. Why?
Analysis
The sender was using a third party bulk mailing service called Send Grid. Send Grid is a legitimate sending source for bulk mail, this is what they do. However in the case of finance.gov.uk they did not change their settings to tell a receiving mail server that mail may also be sent by sendgrid.com. The fix required is at the senders end which of course you have no control over. (But you could be nice and let them know, because the same may be happening everywhere.)
Continue reading Why did this end up in my junk mail?