When you start a new job or join a new group, club, service, or other organization, you may be given an e-mail account to use with that service. You then may set this account up in Mail so you can access it quickly from your iOS and Mac OS devices, in addition to any Web client your provider may use. However, if you are terminated or otherwise leave your organization then access to new e-mail may be restricted and you will no longer be able to receive new messages.

When this happens, you will begin receiving warnings and errors in Mail that mention an inability to connect to your mail service. To manage this, you have a few options:

Disable automatic message checks

If you want to continue browsing through your account’s messages, then you can keep everything as-is but simply prevent Mail from automatically checking for new messages and other updates from your account’s servers:

1. Open Mail
2. Go to Mail > Preferences
3. Click the Accounts section
4. Click your account in the sidebar
5. Go to the Advanced tab
6. Uncheck the options to “Automatically detect and maintain account settings” and “Include when automatically checking for new messages.

Inactivate the account

This option is rarely used since most people would prefer to delete their email accounts; however, if your leave from an organization is only temporary, then you may opt to inactivate the account to prevent Mail from issuing numerous warnings about not being able to connect. This approach will also preserve your messages in Mail, though you will not be able to see your messages unless you re-enable the account.

1. Open Mail
2. Go to Mail > Preferences
3. Click the Accounts section
4. Click your account in the sidebar
5. Under the “Account Information” tab, uncheck “Enable this account”

This will make the account name and icon fade in the sidebar, and then remove references to the account in Mail so you will not be able to view messages from that account. However, the messages are still there so if you wish to view any, then all you need to do is re-enable the account and you will be able to review their contents, even if you cannot connect and download new messages.

Delete the account

When finished with an email account you will likely wish to delete it; however, if you go to the Accounts preferences in Mail you may find you cannot click the minus sign to remove the account once selected. If this is the case, then go to the Internet Accounts system preferences, where you should be able to select and remove the account.

Note that this will remove the account and all of its files from your computer, which will give you no way to get them back if needed. Therefore, be sure to archive your messages before doing this, if you wish to keep them:

1. Ensure your account is set to be “Enabled” in Mail’s preferences
2. Select your account’s inbox
3. Choose Message > Archive (or press Control-Command-A)

Note you can also create your own new mailbox (be sure it is stored “on this mac”) and then select all messages from your account’s inbox and drag them to this mailbox. You can also select all messages and choose the “Save As” option in the File menu to save them as raw source messages or as plain or rich text, which you can then save in a zip archive or dmg image for portability.