If the user has read the message it will not be recalled.
The other condition seems to be whether or not the message was read. In fact, attempting to do so usually results in the recall request calling attention to the original message. There’s no point in recalling a message sent outside your organization. The server only has authority to delete the original message if both users are on the same mail system.
You can’t recall a message if the user you sent it to isn’t a user on your Exchange server. You can’t recall messages from a POP or IMAP mail store. You can’t recall a message you sent to a Gmail address. In most cases it comes down to whether or not the user is connected to your Exchange server and whether or not the message has been read. There are a lot of rules that govern whether or not a message can be recalled. What is Outlook Message Recall? And why does it fail almost every time? Message recall is an Exchange feature that allows the server to reach into a connected Exchange user’s mailbox and pull out the bad message. And, much like every else on the planet, you click Recall This Message only to find out that it never works. Quickly you rush up to the Actions menu to take back that errant email via Outlook Message Recall. Either there’s a glaring typo or a forgotten attachment or you attached a file you shouldn’t have. We’ve all had that moment when we hit send on something only to realize that we shouldn’t have.