Emails held for how long?

[#1]

My wife has her own laptop, and very rarely downloads her emails. Says she doesn't think anyone would send her one!
So, for how long does Plusnet keep unread Emails on its servers? Are they then just wiped, or what happens?
I am certain that the time will be far greater than the gaps between my wife checking hers, so this posting is almost certainly just for interest.
Many thanks.
Keith

[#2]

As far as I remember, if a mailbox containing email has not been accessed for a minimum of three months, then the emails get archived and then Plusnet send a message to the account holder's email address to say archiving has happened and that those emails can be recovered by unarchiving if the customer request it.  However, in my experience I have several times requested unarchiving and it rarely works - even with repeated attempts !

[#3]

@purleigh
Thank you for the information.
Hopefully, it won't come to them being archived and me have the problem of getting them unarchived.
Cheers.
Keith