how to move ebooks from one account to another

I can't answer properly, but a few things.

The ID is not hard-wired to the email address. 

There is an internal ID which is the 'real' fixed id, and (if you manage to login) you can change the email address associated with it.

It looks something like "urn:uuid:ff2ddc22-eca0-46c6-a84d-xxxxxxxxxxxx"

I've copied a post below that shows how to get the internal id from a .epub book that is assoicated with it.

If you've got the new ADE2.0, when you do ctrl-shift-I it tells you the internal ID as well as the currently associated email address.

I'm pretty sure that both the older and the newer ADE remember both the internal ID and the email address.

If you update the email address associated with the ID, ADE catches up with the email address at some point, but I'm not sure exactly how.

I changed the email address associated with my ID a couple of months ago, and both ADE2.0 and ADE1.7.2 are now showing it correctly, but they didn't immediately.

Maybe they sync it up the next time you actually buy/borrow a book ~ but that is pure hypothesis.

The ID is not specifically associated with ADE; it is a generic Adobe ID used for all sorts of other things.  It won't actually have been generated by ADE, and it shouldn't make any difference which version of ADE you were using when you first got the ID.

I don't know if Adobe can access your account based on the internal ID.  Clearly most of the software can and does do its access by internal ID, but it depends how the database is surfaced to the admin staff whether they can access it that way.  It may well be that if you are lucky with an admin they will know how, and that others less well trained will tell you it is completely impossible.

Sorry if that is all a bit confusing: I hope it helps.

~~~

Finding the internal ID.

You can't find it in the .acsm.  The .acsm is downloaded before the book is associated with an AdobeID;

its association with the ID is created when the excrypted .epub file is created/downloaded, and held at the server end.

However, you can find the AdobeID (at least in internal form) from the .epub file.

To see the AdobeID from an encrypted .epub file:

Open the file as a zip archive. 

If you have a good zip archive manager like 7zip you can do this directly.

Otherwise, you must rename the .epub file to a .zip file to open it.

Find the file rights.xml inside the zip; probably META-INF\rights.xml

Inside that file, you will find a section that looks something like <user>urn:uuid:ff2ddc22-eca0-46c6-a84d-xxxxxxxxxxxx</user>

That is the AdobeID.

The ID was stored only in its internal form, and not by the username that belongs to the ID.

However, if you are on ADE2.0 you can use Help/Authorization Information (ctrl-shift-I, cmd-shift-I on Mac) which will show you both the external username and the internal ID.

At least you can check that way if ADE thinks you have the correct AdobeID for the book; but if you haven't it won't remind you of the username you used.

I don't know if Adobe service are able to find the userid if you can give them that internal ID.