That error message says nothing about not recognizing the servers.
Incidentally, Acer is giving you the run-around because the settings
for Windows Mail are identical to those for Outlook Express.
The POP3 protocol has not changed.
What the error message does say is that the server does not like
the username/password credentials you have supplied. If you are
sure that those are correct, then something else is corrupting the
username/password. That 'something else' is likely to be your
antivirus program.
Windows Mail is not compatible with most McAfee
or Norton security programs. Those will need to be
uninstalled, not just disabled.
After uninstalling your non-compatible antivirus, reboot,
then try Windows Mail again. If you still get the same error,
delete that email account, restart Windows Mail, then re-
create that account.
At your convenience, download and install a more compatible
antivirus like the free Avast:
http://www.avast.com/eng/avast_4_home.html
Even compatible antivirus programs will need to have their
email scanning option turned off. For more on this topic see
http://www.oehelp.com/OETips.aspx#3