e-mail addresses appear in my contacts, how to stop that

I had the same problem. And yes they did go into my Contacts. They were shown as new contacts with the contact name being the email address I had used. The number of cards showing in contacts increased by over 100. I am familiar with the previous recipients list in Mail and this was not the issue.

I found that the problem was related to the fact that I was using Exchange. I went into System Preferences, selected Internet Accounts, selected Exchange and unticked the Contacts box. Result - the additional email addresses disappeared from my Contacts.

Hope that helps.

Pleasw help me bring back all my contacts because emails addresses appeared in my contacts.

Thank you

It does not go into your contacts.

All email recipients are saved in a previous recipients list separate from Contacts. The autofill feature when addressing an email pulls from Contacts and from the list of previous recipients.

I know this is no longer current but for new victims like me, this IS a problem with Exchange. If you have an Exchange account active go to System Preferences, click Internet Accounts and uncheck Contacts. You'll lose access to contacts associated with that account, but the inconvenience of re-checking it when needed outweighs the hassle of finding 20 or more email addresses littering my Contacts every time I open it.