Setup with Mail.app for MacOS X
How to set up your e-mail in the MacOS X Mail.app
If you would like to access your mailbox.org e-mails using the Mail.app on MacOS X, please follow the instructions below to set up your account:
1) To start, open the System Preferences overview in MacOS X and then click on Internet Accounts.
2) A list of your online accounts will appear. Add an account and select the option Add a Mail account, then click on the button Create....
3) A dialogue window will appear. There, please enter your name; then, an e-mail address to be used as the sender address of this account (which can be your mailbox.org address, or an alias); and your password. When finished, click the Create button.
4) Now you may choose whether to create an IMAP inbox or a POP3 inbox. Consider which one you prefer as each protocol handles e-mails differently. When choosing IMAP, your e-mails will be kept on the mail server all the time, no matter how many clients you use to read them. Our IMAP mail server is imap.mailbox.org. When using POP3, every time e-mails are retrieved from the server they will be physically downloaded to the e-mail client and then deleted on the server. If you prefer this mode of operation, then the POP3 mail server to use is pop3.mailbox.org.
As a user name, you need to state your main mailbox.org e-mail address (an alias won't work here), as well as the password for your account. Click Next to continue.
5) In the last step, you need to specify a server for the sending of e-mails (SMTP). For this, please enter smtp.mailbox.org, and then again your mailbox.org login credentials. These are the main e-mail address of your account as a user name (don't use an alias), and your mailbox.org account password.