Restoring/Forwarding offline emails from Mac Mail A long time ago I started using Mac Mail instead of my web-based Yahoo email. Then I deleted all my emails from my web-based Yahoo account and kept them on Mac Mail. Now that I've stopped using Mac Mail and I'm back to using web-based Yahoo, I want to know if there's any way I can restore/forward these offline emails stored on my Mac Mail back into Yahoo. There are a lot of emails, so forwarding one by one is not an option.

Someone help?

Thank you!!
Add your Yahoo! email as IMAP and upload your mail manually from the old —presumably POP— storage on your Mail.app.

I haven't tried it myself but in recent OS X versions adding accounts is straightforward. If this is not the case and you have to configure it manually, Yahoo! offers relevant information to that effect here.