I too received a similar email regarding my password. I emailed Logitech and asked them what was going on. Here is the email reply I received:

Recently, you received an email either thanking you for purchasing a Logitech Harmony remote or indicating that the password for your Logitech Harmony Remote account has been reset. This email was sent in error due to a technical issue with our automatated email system. Your Harmony password has not been changed. We would like to assure you that the integrity and security of your Harmony Remote account has not been compromised in any way. We apologize for the confusion as well as any inconvenience this may have caused.

If you would like further information and other tips on customizing your remote please visit the FAQ portion of your Harmony member website. To access, Click “Support”, then click “FAQ” while logged in your Harmony member page.

If you have any additional questions, please feel free to contact us again. Please click the link below for our support hours and contact information.

http://supportinfo.harmonyremote.com

Regards,

Harmony Technical Support