Super Forms 2 sends but returns an empty email

Super Forms 2 sends perfectly well, but the returning email is devoid of text. Well, that’s not exactly true, the only text in the body appears to be a zero. Ironic, huh? And the subject line is entirely blank. One Little Designer must be on holidays— his response so far is similar to my text— zero/missing.
When I look at our account in webmail it tells me that: the message contains part html, but html is disabled.
I can’t see where I can enable it, and ‘view source’ is little help. There is an option to convert html to plain text and view…, perhaps that’s what I’m looking for, but when converted all I get is, literally, a 0. As though the entire message text was 0.

Thanks in anticipation,
PS: Thanks and congratulations to the clever blokes who support us dills.