Services that worked fine yesterday suddenly don't work anymore.
The most likely reason for IMAP, DNS, and web hosting to suddenly stop working is that there is a syntax error in one of the files in your ~/.domtool directory. Admins sometimes need to regenerate all domtool configuration files after making a change to domtool; if one of the files in your ~/.domtool directory has errors, it could prevent other files in that directory from being activated.
To figure out whether this was the problem: for each file <FILE> in your ~/.domtool directory, run
domtool -tc ~/.domtool/<FILE>
If you see any problems, either move the file into a different directory, or fix the problems.
When done, run domtool on each file in your ~/.domtool directory, and everything should be back to normal.
It is highly recommended to keep files in a different directory while testing them, and then copy them to ~/.domtool once you are certain that they are error-free.
If you don't find any errors in your domtool configuration, then you might want to file a support request.
Reference: MemberManual/UsingDomtool.