Recently been receiving a lot of undelivered mail returned to sender replies

Not really enough information provided. At a guess you're using a gmail account (possibly yours) to send emails to domains deemed as suspect by gmails sending mail servers. If this is the case then contact Google Mail support and ask for their assistance. They may tell you to stop sending emails to suspect domains. If you persist those emails will keep coming back undelivered and you'll be contributing in a round-about way to the amount of UBE on the internet.

In what way are you associated with photography.com?

Are you sending mail to them, and those messages are bouncing?

Or are you the owner of that domain and you're having trouble sending or receiving mail for that domain?

Ultimately, the error message is reporting a problem with the photography.com domain which is preventing Google from validating (and trusting) the domain, hence the blocks.

If you own photography.com then you need to update your DNS settings - at the very least add a DKIM record.

If you don't own photography.com then reach out to them and ask them to fix their domain.