Occasionally, when I compose a new email or reply to an email, it is sent to a particular person (I'll call him "John Smith") and not to the person whom I have addressed the email to or replied to. The address appears correct before sending, but is nonetheless sent to John Smith and not to the intended recipient. Some more info: 1) Occurs with any of my email accounts 2) John Smith is the only person that receives these emails in error - never anyone else 3) John Smith appears as the recipient in my "Sent" mail, but not in the address line 4) I have tried deleting John Smith from my contacts - did not fix 5) I am not sure, but it may occur when I delete part or all of an email address in one or more of the address lines and manually enter it (I am sure I have done this with a few of the emails in questions, not sure about all). 6) I am positive that I have not accidentally entered John Smith or allowed Thunderbird to auto-fill his address when these errors have occurred. I am positive that I added the correct email addresses when these errors have occurred. Does anyone have an idea what's occurring here? I have tried searching for an answer to this for weeks (Thunderbird bug, virus, corrupt prefs, etc.). Thanks