Maintain info when jail is in mail! (4,6)
I believe the answer is:
'jail is in mail' is the definition.
I can't tell whether this defines the answer.
'maintain info' is the wordplay.
'maintain' becomes 'keep' (synonyms).
'info' becomes 'posted' (I can't explain this - if you can you should give a lot more credence to this answer).
'when' acts as a link.
Can you help me to learn more?