I have had WP on this particular server for a couple of years and the Contact 7 plugin has worked fine.
Now I installed a MU website on the neighbouring folder. I have two websites on it and the contact 7 form does not work on either of them. It sometimes returns the Message sent ok with a green border and sometimes the message was not sent with the red border.
I know there have been solutions for this but that was mostly because there were problems with the hosting provider's server settings.
I wish there was a good was to debug this. On one of the websited I installed a theme (Kriesi's Coalition) that has its own contact form using the mail() function and that one doesn't work either so I think there is something in the website setting or in the WP multisite features.
Can anybody help please.