title_body: Are ebooks licensed only to a certain email address? I have Adobe Digital Editions installed on my computer.  Adobe Digital Editions is tied to my Adobe ID email address, oldemail@domain.com. 
  
  Over the past several years, I have purchased several (non-public domain) ebooks from the vendor ebooks.com, both EPUB and PDF.  My ebooks.com account is, like my Adobe ID, associated with oldemail@domain.com.  
  
  When I purchase and then download ebooks from ebooks.com, I am given an .acsm file ("Adobe Content Server Message" file).  Once I have downloaded the .acsm file to my computer, I double-click on it, Adobe Digital Editions opens, and the ebook file (EPUB or PDF) is downloaded to my computer and automatically placed in Adobe Digital Editions.
  
  Once the ebook is in Adobe Digital Editions, if I right-click on it and select "Item Info," it says:
  
  Permissions
  Licensed To: oldemail@domain.com
  urn:uuid:########-####-####-####-############
  
  
  where # is a number 0-9 or a letter a-f.  When it says Licensed To: oldemail@domain.com, what does that mean?
  
  My overall question is, are ebooks tied to (i.e., licensed to) a particular email address?  
  
  Are they tied to a particular email address as soon as they are purchased or only when they are opened on Adobe Digital Editions for the first time? 
  
  Another way to ask this question is the following: which of the following statements is true?
  
  
  An ebook is tied to a particular email address as soon as it is purchased.  So if I purchase an ebook from a vendor (e.g., ebooks.com), the ebook is tied to the email address I used to purchase the ebook as soon as I click purchase.  In other words, if I use oldemail@domain.com to purchase an ebook from a vendor, I can only open that ebook using software that is authorized to oldemail@domain.com. 
  An ebook is tied to a particular email address only when the .acsm file is actually opened and the ebook is loaded into Adobe Digital Editions (which itself is tied to a particular email address).  In other words, if I use oldemail@domain.com to purchase an ebook from a vendor, I can open it for the first time either with Adobe Digital Editions authorized to oldemail@domain.com or with Adobe Digital Editions authorized to newemail@domain.com.  However, once I open it with either authorization (either oldemail@domain.com or newemail@domain.com), the ebook is forever tied to that particular email address and I can no longer open it with the other authorization. 
  
  
  My issue is that I want to change my email address, from oldemail@domain.com to newemail@domain.com, without losing access to my ebooks.  To do this, do I need to ask the vendor (i.e., ebooks.com) to change the email address associated with my account, or do I need to just to redownload the .acsm files and open them in an Adobe Digital Editions authorized to newemail@domain.com?  Neither support team is at all clear on what I will need to do.
upvoted_answer: I do disagree with idiotprogrammer's answer because this question does dive into DRM which plays a large part in ebooks.
  
  You could try changing the authorization of your Adobe Digital Editions account, reference: "How do I change the authorization on my laptop" with a re-install.
  
  If that doesn't work you would need to contact ebooks.com. Since you're getting a .acsm file I would 99% think they are using Adobe Content Server.  
  
  
    First, it's ridiculous to think that a DRMed ebook is tied to an
    email. Instead, it is tied to a user account created for a specific
    vendor. Every website under the sun allows you to change the email for
    the account. Even if the sign on you use is the email I suspect you
    will be able to change the email associated with it from account
    management on the user's site.
  
  
  Actually not..  ebooks.com might treat the email address as the ID and use it for validation to prevent transfer.
  
  Your issue will need to be addressed at the vendor if a re-install of ADE is unsuccessful.  To my recollection DRM is scoped to what they have identified as the ID.  In this case your ID is your email address.  You might be allowed to change your email address in the account settings of ebooks.com but I do not have an account there so I wouldn't know.
  
  I did run across this in research: "I figured out the .acsm problem!".