Q: when I save an email to Drafts, I find I can no longer add to it. it seems to be frozen. What to do?

Hello teresafromcambridge,

After reviewing your post, it sounds like you can't edit drafts. I would recommend that you read this article, it may be able to help the issue.

Mail (Yosemite): Save draft messages

Open a draft to continue working: Open the Drafts mailbox (from the Favorites bar or the Mail sidebar), then double-click the draft to open it in the message window. Now you can finish and send your message.

Thanks for using Apple Support Communities.

Have a nice day,

Mario