— From Mac OSX Hints
“Recently, I needed a plaintext list of all emails in my Address Book. Although Address Book has exporting capabilities, it exports all contact information. Needing only email addresses, I did the following:
- In Mail.app create a new message
- In Address Book, select all contacts (Command-A) and drag them to the To: field in Mail’s new message window
- Select the To: field and select all recipients (Command-A)
- Paste the resulting comma-separated email addresses wherever needed
- Last, but not least, delete new message without sending (unless you have something really important to communicate with everyone you know).”