Chat Mailer is an iOS application that supports chat view of IMAP email.
Able to read past emails and build chat view. Folders other than INBOX
and Sent box can be read by specifying your custom folders on server.
Following email providers are supported:

- Gmail
- AOL
- GMX
- Zoho
- Softbank Email(i)
- KDDI AU ezweb (imap)
- Yahoo Japan imap.
- Nifty imap mail.
- EMOBILE imap.

Setting details are described in help. Basically you just type your full email address and password.
Chat mailer will judge your IMAP and SMTP server settings.

The iCloud mail need to setup app password.