If you have an old Orange email account such as Freeserve, Wanadoo, fsmail, orange etc, EE have emailed everyone using those accounts to say they will no longer work (at the end of May I think). They also provide instructions on how to set up an "Out of Office" email so that anyone emailing you via your old Orange account will automatically get a reply that you set up. I've said something like - "This email server is being closed down and I will no longer be able to be contacted via my orange.co.uk address. Please make a note of my new email address which is :- ........." Anyone using your old email before it is closed will get your message automatically. Most email providers will allow you to set up "Out of Office" emails so the OP can do this too.
There are a couple of problems with changing your email provider though. Your email address (together with your password) often constitute your online identity on websites. You will need to change your email address in all your online accounts. Also, many people just hit reply to your emails and never bother to check that they are replying to your new address. You computer tries to be helpful and stores all addresses from the past, including discontinued ones and doesn't warn you, although you should get a delivery failure message afterwards.
It does give you the opportunity to quietly 'drop' some unwanted connections though