Which Exchange Email apps for iPhone 5 allow advanced font and layout controls? What I need in my Microsoft Exchange 2010 mail client:


send e-mails in the text font I want
send e-mails with my HTML signature
reply to e-mails without unformatting the e-mail being replied to
having the sent e-mail look just as it was sent by Microsoft Outlook itself
no artifacts like having the replied e-mail sent as an HTML attachment


Coming from an Android, I had this with Touchdown.

What do you recommend for iPhone 5? What's the best, well integrated with the device, Exchange 2010 mail client?
Try Mail+ for Outlook. It is similar to the native iOS experience. Though it currently doesn't offer all of the features you mentioned, I know there is a new update coming by the end of February which will have rich text editing and better reply experiences. Apple severely limits the ability to use push notifications, so don't expect too many iOS mail clients to provide.