[MlMt] Sent emails copied to inbox?

[Jonathan Clark]

Sometimes - but not all the time - I send an email (without copying 
myself on CC or BCC), and immediately a copy of the email appears in my 
inbox. I'm mystified why this happens, as I don't have any conditions or 
rules on this standard MM inbox, and I don't think Gmail filters could 
do this either. I don't believe I have any other MM clever processing 
bundles active either.

How can I help debug what's going on?

Thanks,

-- Jonathan