How can I tell if my domain is on an email blacklist?

Try the Email Blacklist lookup tool.

"There are a multitude of reasons that email can be marked as spam. If you are lucky, you get a ""bounce"" email, and if you are even luckier, it will have some links to where to go next.

You seem to be in the luckier category. :-)

You should follow the links, and read through and follow any advice. Google and its servers, which I also use for a hosted domain, seem as susceptible as any to being marked as the source of spam.

Unfortunately, if your emails are being marked as spam by the filter on the receivers host or ISP, then it is the person you are emailing who would have to complain, and often there is no way to manually correct the problem.

Most hosted email accounts (like gmail, hotmail etc), will let through more mail, if the recipient has you in their contacts.

In Australia I find Telstra's Bigpond service (bigpond.com and bigpond.com.au) is often one of the most aggressive about filtering, and neither the sender nor the recipient has any knowledge of the missed email, until you discover it didn't get through."