Possible Clues:

• Electrical message
• Medium for messages
• Type of message
• Lover of Homer allowed to return message
• Message from public transport: 'Introduction of electronic support needed'
• Message Marjorie allowed to be returned
• Short sad poem penned in vehicle gives urgent message
• Message sent electronically to be delivered in written form
• Great elm snapped wire
• Vehicle includes The Spanish, for example, in The Wire