Could be a problem at his ISP's end. Is he able to login to his ISP's website and check the status of their email server?
At the moment incoming email to my speed-mail.co.uk email address isn't working at all. Outgoing emails I can still send since I use Virgin.net for my internet connection (speed-mail is my old ISP but I have kept the email address).
All login pages for my speed-mail account both internet and email are currently inaccessible. Biscit who took over speed-mail are currently messing about with their servers and there's no sign of how long it will be before it is fixed. Speed-mail are part of Fast4.