Webmail file capacity

[#1]

I had a serious computer mechanical failure today and I became really worried about my data.  All my data was fully backed up thankfully, with the exception of my Outlook email *.pst file, which I had not backed up for a few weeks, and there was important data there which would have been difficult to replace.  As it happened, the failure was resolved fairly easily, although it entailed getting inside the box.  No harm done, thankfully.
But this was a warning, and I have thought about what other measures to take.  In the past, I have always set my email client to delete emails from the Plusnet SquirrelMail server once they have been downloaded, so as not to clog up the servers.  But I have now changed that, because, by leaving copies on the server, I effectively have a simple back-up of all my email.
Being public spirited, it makes me ask the question "What is a reasonable amount of email to leave on the webmail servers ?"
I cannot find any guidance on this subject, but it would be nice if someone from Plusnet could perhaps enlighten me.  For instance, my Outlook off-line *.pst files contain about half a giga-byte of email in respect of the last two to three years.  I would not wish to leave all that on the servers, as for a start, they are not particularly secure, and so I would still do off-line backups from time to time, and then delete the data on the servers.
But what, as a rule of thumb, is a reasonaale amount of data to store on the webmail servers ?

[#2]

Generally, if you keep it below 500MB, you won't be hearing from us about it.

[#3]

I don't know what the limits are on the server and I am interested to see the repies you get to that question. 
However, copying emails, address book etc, from Outlook is a set and relatively easy procedure.  A CD would take literally 1000s of emails if they are that important to you. However, retrieving them is much more of a hassle, especially in my case because most of my friends are too sloppy with the headers. They just click on the "Reply" and, consequently, the contents often bear no relevance to the heading.  I used to worry about the loss of emails, but I have "survived" total losses several times.  Having backed them up I then realized that I never needed to refer to them, so I now treat them as a little more "permanent" than telephone calls.  Those that I might like to refer to in the future are copied to a folder called "Archives" and one has to be disciplined and do that on receipt.  Others I keep for 3 months.
Alex

[#4]

James
Thanks for that.  As the limit for webspace is 200 M, I thought that webmail might be lower.  But that's helpful.
I presume that if I over-reached, I would be given warning and asked to reduce it before it was removed by Plusnet ?
Secondly, if I move emails from the Inbox to a sub-folder, is there any way of adding further security by requiring another password etc ?  I doubt it, but worth asking.
Alternatively, can they be transferred easily, say, to another mailbox which of course uses a different password ?
hamilton36
Thanks for that.  But backing up is verye asy with Outlook.  I have several  different *.pst files, depending on subject matter, and file everything carefully.  Then I simply take copies of all the *.pst files through my network onto another computer as a quick safeguard, and then in time from there to CD.  You would be surprised how often I go back to them, because anything older than a year is not kept active on my system - except when I need it !

[#5]

you can definitely set up another mailbox and password on the member centre, I use Thunderbird and IMAP and often move from one mail box to another on the server