On my Bold 9790, why are some emails getting Truncated?

Hi, I have a Bold 9790 running OS 7.1 2039 and one particular email gets truncated. I reckon the emails, which are a daily digest from an online forum, are about 40kb. I pasted email into Notepad on PC and it came out at 34kb. Today after using "more all" several times, I finally got "Truncated 20300 bytes" and that was it.
Tried forwarding email from gmail on PC to another gmail account and email opened perfectly on phone.
Strange - any ideas out there??