Unless you have a marketing reason for turning a website its rarely a good idea to turn it off just to make you have less emails, this is demonstrated with this exhange:
[website owner] I would like my websites to be switched off please. I am not using them, nor advertising them at the moment, and therefore I think they should be closed. I will let you know when I am ready to switch them on
[Delicious Webdesign] The last thing you should do to a website if you have any plans to use it in the future is turn it off (or put it offline) This is because you have started to build up a bit of trust with the main search engines Google, Bing and Yahoo and they now know about your site and have now indexed you. You can remove it but the search engines will take it out of their indexes you and put your ‘trust ranking’ back a bit.
As your website aren’t main ones and are barely getting any visitors currently I would say its better for you just to leave them online.
