Berkeley Mailbox (.mbox or no extension):

The email format used by Mozilla, Netscape, Evolution (for local folders until version 2.32), Eudora, and many other email clients.

Maildir (no extension):

The format used by Evolution (for local folders since version 3.0). There is no need to import Maildir files as you can configure a Maildir account in Evolution and point to the folder where the Maildir files are stored.

Outlook Express 5/6 Personal Folders (.dbx):

The email file format used by Microsoft Outlook Express 5/6. For newer versions PST import is recommended.

vCalendar (.vcs):

A format for storing calendar files, which is generally used by Evolution, Microsoft Outlook, Sunbird, and Korganizer.

iCalendar or iCal (.ics):

A format for storing calendar files. iCalendar is used by Evolution, Microsoft Outlook, Palm OS handhelds, and others.

LDAP Data Interchange Format (.ldif):

A standard data format for contact cards.

vCard (.vcf, .gcrd):

The address book format used by the GNOME, KDE, and many other contact management applications. You should be able to export to vCard format from any address book application.

Evolution/Mozilla/Outlook CSV/Tab (.csv, .tab):

CSV (Comma-separated values) or Tabulator files saved by using Evolution, Microsoft Outlook and Mozilla.

Personal Storage Table (.pst):

A file format used to store local copies of messages, calendar events, and other items within Microsoft software such as Microsoft Exchange Client, Windows Messaging, and Microsoft Outlook.