The Mail Viewer looks like a standard Mail client with the Mailbox bar at the left side of the screen and the list of mails on the right side. Only one archive can be open at the same time.
The Mail Detail contains 4 tabsheets with the Message Body, the Attachments, the Header and the MailTags information.
Enter search text into the search bar to search either for From, To, Subject, Body or Attachment. Or search in all fields. A search for "test" will find "test" itself but also "testing" and "a test".
Ordering is done with the menu Browse/Order by, which has the following entries:
Select one menu entry and the current selection of mails is reordered. Any new search also has this order. You can also re-order clicking on one of the header fields. The search order is saved to the preferences.
You can reply to a selected mail in three variations. "Reply to" replies with the selected text of the message body to the author of the mail. "Reply to all" replies with the selected text of the message body to the author and the CCs. "Forward" creates a quoted mail without a recipicient. The mail is created in the currently selected mail application. Because Mozilla is not AppleScriptable, only a new mail with recipient and subject can be created. The message body of a mail cannot be set.
The selected mail can moved into the trash with "Delete Record ...". "Browse/Empty Trash" empties the trash.
"Show All" selects all records in the currently selected mailbox. This undos any search.
View your attachments in the attachment tabsheet. You can change the shown size at the bottom where you also see information about the file type and the size. If the attachment is not a picture then Mail Archiver tries to get a preview of the file. If this is not possible then an icon for the file is shown.
At the bottom of the "Attachment" tab, there is a button with a menu to export the attachments of the current mail.
"Export" saves the currently selected attachment. "Export all" doesn't need a selection to save all attachments. If "Reveal in Finder" has a checkmark, the attachment is shown in the Finder. "Delete" deletes the currently selected attachment.
When an attachment is double clicked it is opened with the associated application. Also an attachment can be dragged and dropped to the Desktop.
New for 3.1 is support for the MailTags plugin for AppleMail, which is shown in it's own tabsheet.