I have issues with the email app ever since I got the EVO 4G LTE in early July. HTC says they are "working on it," and Sprint techs did not recognize the prioblem. While it's not nearly as serios as our lack of signal issues, maybe this is a problem others have encountered and resolved:
Messages are too wide for the screen. There is no "text reflow." And pinching the screen does not work in email. The only way to view most messages without moving back and forth is to turn the phone to horizontal.
Email settings are missing. The manual shows options to switch between plain and html format in the settings menu. Those options are missing from my phone. (Probably not a big deal, unless these omissions relate to the issue above.
Also note: (a). Cannot change setting to allow images to display automatically. (b). hyperlinks do not work in most messages. (c). color-coding on edge of message that shows which type of email (Yahoo or Google) disappears after I open the message. I mention these three minor items because they were not problems with my former phone, the EVO 3D.
I have both Yahoo and Google email. No problems with either separate app.
HTC said they could replicate the problem there, but did not yet know how to fix. Said they would get back to me. That was at least two weeks ago.
I had to return my first EVO LTE (for connection problems and capacitive lights did not work), but I had noticed the same email problems on both devices.