Can I use multiple gmail-based accounts with the same username (but different domains) with Mail.app & IMAP? A recent mail file corruption has led me to finally putting Eudora to bed.  Since my personal email has been backed by gmail for a few years, and my work email is a Google apps email account, I figured I'd take advantage of server-based storage to not worry about fixing Eudora mail files, but just use IMAP to sync up with the servers in Apple mail and be done with it.

Well, my personal account and my company account are both the same user name, i.e. username123@gmail.com, and username123@company.com.  (Not real.)  And it seems like this is causing a collision in Mail.app.  On editing the initial mail config setup, I get an error:  "Invalid Directory:  The account path /Users/.../Library/Mail/IMAP-username123@imap.gmail.com is already being used by the account Company Mail".  

I was concerned by this, but it did seem to be busily downloading mail into the "All Mail" folder for the new account, so I let it run.  But, yeah, it seems broken.  What should be individual inbox folders for each account show all the same sets of messages.  That's no good.

A funny thing is that I've had these same two accounts on my iPhone, with IMAP, and it keeps them straight!

So, am I doomed to not being able to use Apple Mail in this scenario?

Update: Today, the two inboxes look separate, after a restart of Mail overnight.  However, I still get the same error when I try to change the personal account to send through an alternate server, so I think there is still a problem here.
Follow these steps:


Open Mail and delete each of the conflicting accounts. Close Mail.
Go to ~/Library/Mail/ and make sure any IMAP-username123@imap.gmail.com folder has been deleted. If there is any such folder left, delete it now.
Open Mail and create one of the accounts and let Mail load your messages. Close Mail.
Go to ~/Library/Mail/ and verify that a folder called IMAP-username123@imap.gmail.com has been created.
Open ~/Library/Preferences/com.apple.mail.plist. If you have installed Xcode, this file will open with Property List Editor. Otherwise you can download a free trial of PlistEdit Pro to open this file. Using a plain text editor with .plist files is more difficult.
With the .plist file open, click the disclosure triangle for MailAccounts. Here you will find Item 0, Item 1, etc.
If you click the disclosure triangle for each of the Item headings, you will find that one of them has the value username123@gmail.com or username123@company.com for the AccountName key, depending on which account you created in step 3.
Change the value for AccountPath for this Item so that the path will not collide with that of the next account you are to create.
Save and close the .plist file.
Open Mail and let it reload your messages. Close Mail.
Go to ~/Library/Mail/ and verify that a folder with the path value you provided in step 8 has been created. Delete the old folder called IMAP-username123@imap.gmail.com.
Open Mail and create the remaining account normally and let Mail load your messages.