I know it should be obvious but perhaps there should be a message when someone is setting up an EI account warning them that they may receive e-mails from EI. It's only a matter of time before some genius specifies their work e-mail address or worse still an address to which their wife has access.
If they are using Outlook Express as an e-mail client for example the likelihood is that they would have asked Outlook to save their password when first setting up their e-mail account and they are not prompted for a password at all.
Jimbob