I have the same problem on a handful of sites. First it was one, now another, now I am checking all of them and a bit frightened that I will have a lot of work to do recreating forms! (lottsa sitessss ya)
I use CF7 to Database Extension plugin and all submissions are there (thank goodness!) but nothing coming to inboxes. Very very frightening Galileo. Have tried all sorts of troubleshooting. This is on DreamHost. I have other site on VPS.net and the forms are working, it seems. Very good, I am one step closer to understanding this perplexing issue.
Also I think it's noteworthy to quote this person from this other post:
Posted 3 days ago #
I'm having the same issue with any email address hosted by google. i,e, gmail.
The mail doesn't even make it to my inbox / spam / junk folder. Seams to get highjacked by the server at some point.
Private ISP email address work fine - comes through to the inbox no problems.
I don't have a Private ISP email address to test this out on right now, but that's interesting. VPS.net does things differently than DreamHost.
Maybe there is something to do with DreamHost's and other general shared hosting providers' mail servers that don't digest well CF7's headers or something like that.
My hope is for Takayuki Miyoshi to have insight as to why this is happening, or somebody more knowledgeable than me on reading email logs etc. Thing is, the plugin is sending the emails ... and I'm pretty sure the plugin uses WP's built-in email engine, whatever that is .. some simple PHP thing, I think ... so ... what is the problem???? this is what confounds me .. and keeps me awake right now.