Adding Real Names to IMP when composing?

[duster@prostreet.net]

I have working IMP 2.2.4/1.2.4 Horde running with virtual domains.
Now IMP users are asking that when they compose a mail, the sender's Real Name 
is 'john.doe@virtualdomain.com' ,not 'John Doe'

If i allow users to change 'From' address (default.php), and they put a real 
name when composing, then the sender will be John.Doe@localhost.domain.com ,and 
they don't get any answers back.

Do you have ideas, or solution for this ?

Thank you,
Kimmo Hedman
Finland