Esnouf, understood to be on gardening leave ahead of joining an as-yet-unknown new employer, is believed to have departed the company in recent weeks.
A spokeswoman for E.ON said: ‘We wish Guy the very best. He has made a significant and important contribution to E.ON during his time with us. Internal and external comms will continue as planned by our current team for the immediate future.’
Esnouf joined as head of corporate and internal comms in 2008 and recently explained to PRWeek that he had been working on better customer engagement.
This included overseeing the launch of the Reset Programme in 2011 and creating a focus group involving Mumsnet founder Justine Roberts, among others.
Before his time at E.ON, Esnouf spent a year and seven months as a senior director of comms for Microsoft in the US, which included working with company founder Bill Gates.
Earlier in his career, Esnouf was also political correspondence secretary to Prime Minister Margaret Thatcher.