Error with Mail

I followed the instructions on this page:
http://wiki.dreamhost.com/Mac_OS_X_Mail_10.4

To set up IMAP email through OSX. Now everytime I launch Mail it comes up with an error saying:

"The server error encountered was: Mail was unable to verify the identity of this server, which has a certificate issued to "*.mail.dreamhost.com". The error was:"

Does anyone know how I can undo Step 2 - Modify /etc/hosts?

Thanks for your time

If you have a root power text editor, just edit /etc/hosts and delete the last line. Here's another way:

# sudo -s
# cp -p /etc/hosts /etc/hosts-backup
# cat -n /etc/hosts

this should display hosts file with line numbers. Take note of how many there are. Let's use 11 for example. You want to take it down to 10.

# head -10 /etc/hosts > /etc/hosts-new
# mv /etc/hosts-new /etc/hosts

I've only tested on Linux, but it should work, or work with similar options. If not, to get back to current:

# cp -p /etc/hosts-backup /etc/hosts