B. Mann Consulting

Update: It's ridiculous how simple this is in reality, except I haven't seen it listed anywhere. This MacMegaSite article (which is actually comparing Entourage and Mail.app) talks about the solution:

Mail.app also handles multiple addresses better than any other email program. With everything else, you need to create a separate account for each email address, which can be a pain if you have several different addresses forwarded to a single mailbox. With Mail, you simply list all of the addresses associated with the account separated by commas.

I'm happy to report that all additional email addresses are listed in the drop-down "From" field.

So, you can ignore the rest of these instructions, but I will keep them for posterity. You may still want to enable rules that filter based on the "To" field if you want to keep the mail separate.

Old Instructions

This has only been tested with/requires:

• OS X 10.2.x (Jaguar)
• a POP account
• another, forwarding mail account that gets delivered to the POP account

It may very well delete all your mail. I would recommend backing up your mail folders first.

Recently, marian wanted a solution for Mail.app. She had a forwarded mail account (let's call it "volunteer@otherdomain.com") that sent mail to a "real" account (let's call it "me@domain.com"). Since the forwarding email isn't a "real" account, you can't setup a separate account in Mail.app, which would allow you to customize your full name, have a separate inbox where the mail gets delivered, etc. You also have to manually change the address when you're sending mail, instead of being able to choose it from the drop down list of addresses.

The solution is to trick Mail into thinking that the forwarded email is a "real" account.

1. Create Folder to Store Mail: In /Users//Library/Mail, create a new folder to hold email from volunteer@otherdomain.com (the forwarding account). You can call it whatever you like.
2. Create New Account:In Mail, create a new POP account identical to the real account (me@domain.com) that receives the email from the forwarding account.

   You can change the email address to volunteer@otherdomain.com, as well as the Full Name. Under the "Advanced" tab, uncheck the following:

   • Include when automatically checking for new email
   • Remove copy from server after retrieving a message

   For "Account Directory", hit Choose and select the folder you created in the first step. This is because for the folders that Apple generates automatically, it uses service + user account + mail server for the name, which will be identical to your "real" account.

3. Create mail rule: Go into your Mail preferences and select the Rules button. Create a new rule that says:
   
   [To] [Contains] volunteer@otherdomain.com
   
   For the actions, select:
   
   [Transfer Message] to mailbox [inbox of volunteer@otherdomain.com]
   
   
   
   Now, whenever you check email with your real account, anything that is addressed to the forwarding account will automatically be sorted into it's own Inbox. When replying to email from there, the account will be set to the forwarded account, which means it also goes into it's own folder in Sent.

If you have any problems or questions, post them in the comments.