MailArchive supports more mail providers than you think.  All MailArchive needs is an IMAP interface.  Just add a new IMAP account under settings.

Here are the server details for the more well-known ones.

Yahoo!

Yahoo! uses a non-standard IMAP server, which is supported by MailArchive v1.3+.

Server:	imap-ssl.mail.yahoo.com
Encryption:	SSL/TLS
Port:	993
Username:	<you>@yahoo.com