@Vikki_M wrote:
Snip...
These are typically deleted within 90 days of the broadband account being closed.
...Snip
After 90 days, not within, there's a legal distinction between the two!
Within 90 days implies that they can delete it the day after you leave, actually you have a 90 day 'grace period' in which you need to make alternative arrangements - and I don't three months is unreasonable, to be honest.
Now in reality your email may well continue to work for far, far longer than 90 days, but it can and probably will, just vaporise at some point after that with no further notice.