On rare occasions there may be a time when adding or removing accounts cannot quite finish the background task as required which is out of all our control, especially when a full hosting account has been migrated.
If you are trying to add an email account and cPanel states, the email address already exists but it is not in the list then this will be due to the "paswd" file which keeps a list of all your email accounts already has this address listed in there and so due to this cannot be created.
ADVANCED USERS ONLY
To locate and fix this issue simple go to the file manager or log in to your FTP client and then navigate to the /etc/ folder and then go into the folder which says your domain name you are intending to add your email account into.
Once you have opened this folder you will see a file called passwd, open this file to edit, and then find the line of text which has the email account you are trying to add. The line of text will look like this.
enquiries:x:1102:1103::/home/cpanel-account/mail/danumhost-test.com/enquiries:/home/danumxx1
enquiries are the email account which would be enquiries@danumhost-test.com so there for if this is the line which should not be there simply delete this line making sure other lines are not affected.
If you would like a member of our team to do this for you, please feel free to ask.