There are two addresses you might want to change when you use a forwarding service for your incoming mail. Both are found on the General page of the Account Properties dialog:
Tools -> Accounts -> Mail -> Properties -> General
E-mail address: ..appears in the From: header of your messages
Reply address: ...appears in the Reply-To: header
The Reply-To: address will be used when your recipient clicks the "Reply" button while viewing your message. If it is blank, the reply goes to your From: address.
Most Internet Service Providers require authentication when you log on to send email. If you see an error like this:
The message could not be sent because the server rejected the sender's e-mail address. ... Server Response: '530 authentication required ...
then you need to check the "My server requires authentication" box on the Servers page of the Account Properties dialog. Normally, you will use the same login name as when you check for incoming mail, so leave the default settings as is.
You can set up your email forwarding at box67.com to handle spam in one of two ways - tagging it with the word '[spam]' at the beginning of the subject line, or simply deleting it. Tagging it will allow you to review the discards for possible false rejects. To avoid cluttering your inbox you can set up Outlook Express so that messages tagged as spam are diverted to a special 'spam' folder for later review. There are two steps to this process.
Start Outlook Express.
Right click on Local Folders. Select "New Folder ..."
Enter name of folder as 'spam'.
Tools -> Message Rules -> Mail ... -> New ...
Select the checkboxes, and give the new rule a name.
Click the link contains specified words, and enter the tag word '[spam]'
Click the link to the specified folder, and select the new folder.
Note: If you have other rules also, you may want to put the spam rule first, so that none of the spam gets into your other folders.
The effectiveness of our campaign to Stop Spam at the Source, depends on rapid feedback from recipients. When you see spam that has an empty  tag in the Subject line, that means it bypassed our filter, because the sender has a good reputation. It is important that these few spams be reported promptly. A reputable sender will take immediate action to shut down the source of that spam, and save millions of recipients having to waste time with it. If the spam from that source continues more than a few hours, the sender will lose his A rating.
To report  spam, forward the message to email@example.com. Be sure to include all the headers. In Outlook Express, you can view these headers by selecting the message in your Inbox, then click File -> Properties -> Details -> Message Source... Copy everything from the first line down to the first blank line, and paste these headers at the top of your forwarded message.
To see the sender's response to your report and any actions taken by rating services, visit http://open-mail.org/reports.
At this time, we are taking action on  spam only. Any message that has been through our spam filter has already been reported in the statistical totals for each sender, and any sender that cares to look, has access to these statistics.