This tutorial provides some insight into Apple Mail structure and how to administer the mail accounts. If you use the Apple Mail client to access your email accounts you may have found that modifying your account settings is difficult. Setting up a new email account is fairly straight forward and you probably had little difficulty entering the server information for your mail service provider. Unfortunately, there always is a time when the settings must be changed, either because your service provider changed a URL or you decided to go with a cheaper/better service provider. The first thing you may have noticed is that you cannot change the name of the “Incoming Mail Server” for your mail account. If you select Preferences under the Mail menu heading, you will discover that the name of the Incoming Mail Server is grayed out. While any other setting may be changed, you may not change the name of the “Incoming Mail Server” once you set up the mail account. The reason for this is very simple. Apple uses the name of the “Incoming Mail Server” as a name for a directory for all of the account mail data. Since changing the name of the “Incoming Mail Server” would require that all references to the directory would have to change, Apple decided that it would just make things simple and not allow any changes to the “Incoming Mail Server” field. So what to do if you have to change your “Incoming Mail Server” name? The easiest solution is outlined in the following steps:
Refer to the detailed descriptions below if you need help with any of the steps or want more detailed information about the file structure for the Mail client.
Creating A New Mail Account: Because Apple decided to use the “Incoming Mail Server” as the name of the account directory, you can name the mailbox for the new account that you create the same mailbox name that was used in your old account. It may look a little strange to have two mailboxes with exactly the same name but trust me, because the mailbox name is just an alias for the actual account, the Mail client will have no problem and will sort everything out. To create a new mail account, select Add Account from the Mail drop down. When the pop-up window appears, select add other mail account and continue. Then you should just enter all of the appropriate information for the email account on the setup screen. If you are a little unsure about what to put in all of the fields you can see all of the email account setup for the old account by selecting Preferences from the Mail drop down and then click on the appropriate mail account to display all of the settings.
Copying Emails From One Account To Another: Mail can be copied or moved from any mail account to any other mail account. Mail does not seem to make any distinction between sent or inbox mail so you can copy or move mail in any way that you wish. To copy or move mail you must first select the mail application. Once the mail application is open you should see all of your mail boxes displayed in a column on the left side of the mail window. If you do not see the mail boxes, you need to click on the “Toggle Mailbox List” icon at the top left side of the mail favorites bar. The Mailboxes column should open on the left side of the mail boxes window. Next, you need to open the mailbox from which you want to copy or move the mail. For the purposes of this tutorial you would open the old account's inbox mailbox by clicking on the mailbox. Next, you need to select all of the mail in the mailbox by selecting Edit from the Mail command line and then Select All from the drop down menu. Finally, all you have to do is select Message from the Mail command line and then Move To or Copy To from the drop down menu. You will then see all of your available mail boxes and can select which ever one to which you want move or copy the mail. Why the Select All and Move To/Copy To commands are in separate drop downs is a mystery to me but that is just how Apple choose to set up the menu structure.
Deleting A Mail Account: Deleting a mail account is very simple. Just select Mail from the Mail command line and then Accounts from the drop down menu. Next select the account that you want to delete from the left column on the new widow that appears and then click on the minus sign at the bottom of the left column.
Mac Mail Client File Structure Basics: All of the files for the Mac mail client are stored in the path /Users/Username/Library/Mail. Where the Username is the name of the current user. In other words if you user name is Joe, then your mail is under /Users/Joe/Library/Mail. Of course you cannot view the subdirectory Mail using the Finder application. Apple very wisely has hidden all of the directories for system level stuff from the view of the general user. If you want to look at the mail files you have to use the terminal program and your favorite shell. The default for the apple terminal program is the bash shell so if you are familiar with bash it may be interesting to explore the mail file structure. Within the subdirectory Mail there should be just two subdirectories V2 and V3. Accounts.plist is one of the more interesting files and is the only file found in the subdirectory V2 and is in a subdirectory called MailData (V2/MailData/Accounts.plist). It contains most of the account setup data. All other files are stored in subdirectory V3. The inbox directory for each of your accounts is found in a subdirectory that will end in the name of the incoming mail server. As an example, if your email is a POP account and it has the email address myaddress and the incoming mail server pop.myserver.net, then you would find your inbox directory in the subdirectory POP-myaddress@pop.myserver.net. Editing any of the files in subdirectories V2 or V3 directly can be risky since there is a lot of linkage between files and you may mess up the references between the files. You have been warned. Subdirectories V2 and V3 can be copied to another drive if you want to make a backup or would like to copy the entire email structure to another computer.