How to change an email of an agent to an email of a deleted agent

This article can be helpful when you are trying to change an agent email to an email of a deleted agent

A) you can't change the email address of an agent to the email address of another agent or an agent that has been deleted. However you might be able to work around this limitation in these 4 steps:
 

1) undelete the deleted agent account newemail@example.com like described in point (B)
2) change his/hers email address to something useless (abc@example.com or similar)
3) delete agent abc@example.com again
4) change the email address of the desired agent to newemail@example.com

B) you can create agent with the same email as an agent that has been deleted. This operation 'undeletes' the deleted agent. This is the feature to be used concerning an employee who returned to your support crew.