Outlook fails to send (AOL): says error 554, Txn failed:debug?

[NeilCoulson]

Outlook fails to send email, saying "error 554: transaction failed". The
account is with AOL (so, clearly, I think it's probably AOL's fault, as you
would...).

However, I'd like to debug the Outlook <---> AOL server transaction
more...is there a debug option or logfile or anything I can use to see why
the "error 554" actually happened?

Thanks,

Neil.