MSN has some special rules. People using MSN Explorer will need to do the following to get Outlook Express to work when sending email.
If you are using Outlook Express with multiple e-mail accounts from different Internet Service Providers in addition to MSN Internet Access, you can no longer send e-mail from your other ISP accounts when you are signed in to MSN.
MSN does not provide support for accessing e-mail from other ISP accounts through MSN. If you want to continue to do so while you are signed in to MSN, you must re-configure your Outgoing mail (SMTP) server information to ensure that all of your outbound e-mail is sent through the MSN SMTP mail servers. To do this, follow the instructions below. Repeat these instructions for each additional account you have set up in Outlook Express.
Start Outlook Express.
Click Tools, and then click Accounts.
Click your additional ISP account name in the list.
Under Outgoing mail (SMTP): replace the existing server name with smtp.email.msn.com.
Under Outgoing Mail Server, select the My server requires authentication check box.
Select the Log on using option.
Type your MSN user name in the Account Name box. Do not include the domain portion of your user name (the part that begins with the @ symbol).
Type your MSN password in the Password box.
Select the Log on using Secure Password Authentication check box.
Of course, this is assuming you're using Outlook Express.
There is no best host. There is only the host that's best for you.