I am trying to promote civiCRM at my governmental organisation in London and I would be very grateful if I could visit another organisation that uses several functionalities to see how it works live. Mailing and campaigning are the most important features for us. Thank you all for your time. Romina.
Pleased to hear that you want to promote CiviCRM!
This may not be the best place to ask this question. You may have better luck on the CiviCRM chat site.
Alternatively you could search for a CiviCRM partner based in London and ask if they can help.
You may also be interested in the CiviCRM meetup in London.
Of course there are also the demo sites if you want to try it out for yourself.
I hope that helps. Good luck!