Advantages of a Plusnet email account ?

[#1]

I have only recently joined Plusnet from BT and would like to know the pros and cons of taking out a Plusnet email address as I
Already have Yahoo! And gmail accounts.
Q1. Does Plusnet email offer me any advantages over my other free email accounts ?
Q2. If I ever left  Plusnet for another ISP what would Plusnet do with my  email account ?
      Let me continue using  free of charge ?   Let me continue using it provided I pay for it ? Cancel it ?
Couldn't seem to find the answers in the FAQ's
Thanks.

[#2]

Part 2
After leaving the email account would be lost unless you pay to keep it for £20 per year http://www.plus.net/support/service/policies/cancellation.shtml
Part 1
The advantage of Plusnet email is that you can set up multiple email addresses for use with various suppliers and pick up the emails from them with the catchall
You can then block any of them if they start generating spam
I would do that as well as your free email which you can take with you if you leave

[#3]

Thanks very much  OldJim for your full reply

[#4]

Another benefit of the PN email system is you can arrange to have your own domain name hosted here.  This has massive benefits for the future.
After getting a domain name, rather than telling people your email address is bazzer@username.plus.com you give them bazzer@yourdomain.co.uk
If in the future you change ISPs you can then 'redirect' your domain to your new ISP.  You still get your email and you do not need to tell the world that (consequential to changing ISPs) you have a new email address.
It is similar to number portability when you get a new mobile phone.

[#5]

Even better is to have a domain name and email service that is completely independent of ISP.  Not free, but dirt cheap and completely flexible...

[#6]

Thanks Chaps.
I can see that I'm going to have to investigate getting a domain name 
Presumably I could have several different email accounts on the same domain name e.g bazzer@yourdomain.co.uk  for me and
her_indoors@yourdomain.co.uk for my wife ?
Would I be able to access domain email accounts from all of the following, like I do at present with Yahoo! mail and gmail  ?
a) a web browser
b) Mail app on iPad 
c) Mail tool on iMac 
and what are your thoughts on IMAP  v POP access ?
Thanks again

[#7]

Hi Bazzer,
Not sure if I'll get in to trouble with the mods for "advertising" however I do all of my domain registration with LCN.com - I have had a new domain registered and hosted with PN within 48 hours before.
HOWEVER it is worth double checking with someone @PN via here - can you get a .co.uk domain on your account for free (if its an old one) or for £1 per month or will you have to pay a £30 hosting admin fee for 'bringing in' a pre-registered name?  The rules are not overly clear.
Essentially @yourdomain.co.uk points to @yourusername.plus.com - you can configure whatever email addresses you want here - https://portal.plus.net/my.html?action=myemail&s=1&redirected=yes&?membermenu=emailsettings - ASSUMING you have the PlusNet email option on your account.  IIRC more recent residential accounts need to ask for that option.
IMAP or POP3...
These days I never use POP3 - it can make things very difficult as soon as you have more than one device you want to use against the same emailbox.  If you use more than one device with POP3 on the same mail box - received emails could become "fragmented" across those devices and sent emails are only visible on the device which sent them.
With IMAP configured correctly all devices see all emails and if you loose a device (or it crashes) the emails are all still on the server.  That tough could be the down side, you need to consider what you retain as PlusNet offer just 1GB for email storage.  Remember that with most IMSP clients deleted items get moved to the TRASH folder and remain there (and therefore on the server) until you empty the trash folder.
On all IMAP devices I recommend configuring them to place SENT / DRAFT / DELETED mail items on (into) the server (folders).
HTH,
Kevin