I can read my work emails on my own phone. Just received an email from work saying that the security on my current phone (Samsung Galaxy S8) isn't up to scratch any more. There will be no further security updates for this model.
Choice is an updated phone, or loss of access to work emails.
Upgrading/transferring everything across seems to be the only solution. Pretty sure last time I upgraded I used "Smart Switch" which, if memory serves, was pretty good.
Or just keep my current phone and not look at work emails, unless at work.