I have tried the setting from the above site a few times and, again, just
have a few minutes ago.  I note the site says it is not available on PAYG:

Note: The "Mobile Web" service must be enabled for these settings to work.
Contact o2 Customer Services to get this enabled. *Not available on PAYG*

which begs the question why your wife can email from her PAYG V3i and I
cannot.

I have spoken twice to 2 different O2 reps, once before your reply and once
just now.  Both say O2 do not support sending emails.  They say go on to the
phones browers and send emails, which not what I want. (Presumably this is
what your wife does?)

What I am after is to simply type in a text and send to an email address
just like I did with all my previous mobile phone that I did not have to set
up.

O2 say the new PAYG phones do have that facility, which I find strange.

Bobby