strange email from UKVI?

[sarah3333]

My partner has applied and received a six month visitor visa. He picked up the passport with the visa in it on Friday and then got this email yesterday:

'This email is about the online Visit Visa visa application for xxx.
This application is reaching the date of expiry. If you do not sign in again before Aug 20, 2017, the application will be deleted. This is done to protect your privacy.'

We signed in and it said 'the rules have changed and you should resubmit details'. There is no record of the previous application in his account.

So do we have to do anything? I don't think it's a scam but it does seem strange. Can anyone help explain what this email means?!

[Sedanday]

I got this same email today
I applied in And got my visa in July.
Not used it yet
Although friends I applied with same day have travelled and return and didn't have any issue
So it may be a system mistake.

Because i was told they've changed those handling immigrations and visa to a new company (something like that) so I really don't know. It may have played a part