Nonsense in bank's vacuous email (8)
I believe the answer is:
doggerel
'nonsense' is the definition.
(I've seen this before)
'bank's vacuous email' is the wordplay.
'bank' becomes 'dogger' (I have seen 'A bank' mean 'dogger' so perhaps 'bank' could also mean 'dogger').
'vacuous' means to remove the middle letters.
'email' with its middle removed is 'el'.
'dogger'+'el'='DOGGEREL'
'in' is the link.
(Other definitions for doggerel that I've seen before include "Nonsense verse" , "William McGonagall's kind of poetry?" , "Rubbishy verse" , "not great poetry" , "Irregular comic verse" .)