Intended to be old-fashioned about electronic notice (10)
I believe the answer is:
Here is my best explanation:
'intended' is the definition.
('designate' can be a synonym of 'intend')
'old-fashioned about electronic notice' is the wordplay.
'old fashioned' becomes 'dated' (I've seen this before).
'about' is an insertion indicator.
'electronic' becomes 'e' (as in e-mail or e-books).
'notice' becomes 'sign' (I've seen this before).
'dated' placed around 'esign' is 'DESIGNATED'.
'to be' acts as a link.