Hi Smelter, welcome to the community! Thank you for posting.
Sorry to hear you are thinking of leaving us.
Huge thanks to the community for their insight and support on this thread so far.
You can see more advice and FAQ's on Email here.
They are correct in advising that your email account should be deleted automatically within 90 days of the account closing.
We do not currently offer a service for forwarding emails or retaining access to the address without active services.
There have been cases where this has taken longer to complete than expected, however I would strongly recommend not relying on the email address as a primary account following the termination of your services.
My personal advice is similar to that of Ceonoby - if you are reliant on an email service it is best to have this separate from your ISP to protect its longevity. There are such a wide range of options that you can tailor to your needs.
Let us know if there is anything else we can help with!
All the best.
Molly