Re: ,HTML/PHP contact form not sending to O365 Email
Hi @OliverKeay. Thanks for being part of GoDaddy Community! That error would generally mean that the server you're sending email from is on an RBL (real-time blackhole list) that O365 references to filter email. If the hosting server is also on GoDaddy, that's something that you may want to review with our hosting support team. In some cases, a de-list can be requested. However, the issue may clear up itself within 72 hours. I'd recommend getting in touch with support so they can review the situation.
JesseW - GoDaddy | Community Manager | 24/7 support available at x.co/247support | Remember to choose a solution and give kudos.