Note:- Replace username with your account name.
First, you need a mailbox, preferably with all of root's old mail already in it.
sudo cp root username
sudo chown username username
sudo chgrp username mail
That creates a mailbox for your username with the appropriate user and group permissions. The contents of the mailbox are a copy of root's mailbox.
Now you need to forward all of root's incoming mail to your inbox.
sudo gedit /root/.forward
Enter the following line save and exit the file
Now, you will receive any mail sent to root. To make things more convenient, let's set up Evolution to read the mail.
Change the permissions of /var/mail directory if you get any permission errors in Thunderbird or Evolution mail client
sudo chmod 777 /var/mail
Open up Evolution. In Tools -> Settings -> Mail Accounts, click Add. Enter your Full Name if you wish, and your local mail address username@localhost, then click Forward.
For server type, select "Standard Unix mbox spool or directory." For Path, enter /var/mail/username , then click Forward.
The options on the next screen are optional.
On the next screen, select Sendmail for the Server Type, then click Forward. Name the account however you wish. Use username@localhost, Local Mail, or something similar. Now you're finished.
To test, compose a mail to root@localhost and send it. Then click Send/Receive. You should see the new mail pop up in your inbox.