Standard Unix mbox Spool Directory account settings
Account Editor
Mail accounts can be added by choosing File ▸ New ▸ Mail Account or via Edit ▸ Preferences ▸ Mail Accounts ▸ Add. The steps are mostly the same as for the First-Run Assistant, except for not getting asked whether to import data from other applications or to restore from a backup file.
Mail accounts can be edited via Edit ▸ Preferences ▸ Mail Accounts ▸ Edit.
The following settings are available when editing an existing account:
Identity
Here you define your name and your email address.
Optionally you can set a Reply-To email address (if you want replies to messages sent to a different address), set an organization (a company or organization you represent when you send email from this account), your default signature for this account, and email aliases.