After moving to new webhotel; no emails recieved on certain forms

Hi. I've just moved a old site to our webhotel, updated everything and installed Gravity Forms instead of C7.

Now, when I make a simple form, where everything is "untitled" with only one "single line" form, it sends mails to me. When I custumize the form further, giving it names, but still use single lines, the mails doesn't get sent. It has nothing to do with this; http://www.gravityhelp.com/forums/topic/submitting-forms-to-emails as I can recieve mails when the form is ultra simple. Please help me. Tried everything; complete new form etc.

Any news around for this? It's so frustrating :)

And happy new year! :)

I did follow the Wordpress-guide for moving to a new server. I've used that 50 times before (at least) and it always works out perfect. I moved sites like this a dusin times before; sites that is indeed very similar to this one.
Now; the simple form on the page works fine (under KONTAKT, mailing to the same email), and the more advanced one (in sidebar) is the one not working, even though I deleted the first non-working form, and build a completely new one. I have one (used to function) other form at another domain (same webhotel), that is not working either. Talked to our webhotel, and they had nothing to say. They haven't changed anything.

Did try your migrating tool; saying everything is fine, but still no mail. Tried other mail adresses, and also one at the same domain and webserver; no luck.

Maybe a down-grade of GF would work..?