It happened in a weekend when I was away from home, and while I was in a place with poor Internet access, and it took me a while to figure out what happened. Initially, I thought that the mail server provider had some issues (that was the trigger that something was wrong since I was unable to receive mail), but their website didn't mention any problems. Even the web-mail interface worked properly. The next step was the DNS servers.
The DNS servers carried the proper information for the mail servers, etc., but I wasn't able to resolve anything regarding my domain. Next, my registrar; Hover (formerly known as DomainDirect).
Reason for checking the registrar is that I have several domains that need renewal in the first quarter of every year, and perhaps something went wrong there.
Logging in to my account gave me the reason for my outage; two of my domains were in a suspended state.
The reason for the suspension was that I had to verify an email address they had on file. Only problem was that this particular email address was no longer in use. Thankfully, I was able to change the mail address on file, and the verification process could continue. After the verification the websites and e-mail functionality was restored within a couple of minutes.
This left me with a nagging question;
Why is it that the e-mail for renewal is (or can be) different from the verification process? And if this can (or needs to be different), why can't they notify the every email address on file that something bad is going to happen?....