Password Reset Mail is not received

Hi All,

I have a user ID with email ID abc@def.com where the User ID is abc. I deactivated this user and creating an another user called abc1, and the email ID is abc@def.com

Now the User has forgot the password and click on the forgot password link on the cloud login screen. 

1.He didnt get any email

2. From Admin access i have clicked on Password reset. But still he was not able to get the password Reset Mail.

I have Checked the Email Box in Admin console and remaining all the other Mails are triggering but for only a single user it is not.

I also checked if the Mail address is correct or not. and it is correct mail address. 

Also we checked in Spam mails in mail box too,...

Any Help 

TIA :)