I have checked
http://www.downforeveryoneorjustme.com with my own website (cpanel also) and with Vivaciti's forum and main site, all are down and have been for over an hour now.
Yes, your website and forum and my own hosted website has been mainly unaffected by this mail server problem, until today, this afternoon.
I never phoned up about the problem, but opened a support ticket, when I first noticed the problem, about a week ago.
I know web hosting servers have issues on the odd occasion, but this mail server problem has been ongoing and is affecting my communication with customers and missing emails, now the website going down, means I may have to move it all and change what I can in other places, all today.
My email client Forte Agent when trying to retrieve emails states an error: unable to find address of server
Apologies if I do not have enough patience, but I have been patient for the last week with these errors and for most of it unable to send and receive emails.