Setting up mail on Mac OSX El Capitan

[#1]

I have a problem......
setting up Mail on a new Mac with El Capitan for my Mum - and can send mails OUT but not received them !!
Checked settings many times CAN ANYONE HELP / ANY SUGGESTIONS WELCOMED
PlusNet have no guides for latest OS X and web chat with them was not fruitful !
Thanks
Simon
[Moderator's note by Mike (Mav)  all caps removed from the title as per the Forum Rules

[#2]

Does the setting change advised in reply #1 in the Mac OS 'El Capitan' - Email settings? topic help?

[#3]

Nothing there to help would appreciate any other views please -!

[#4]

I would probably try deleting the settings that you have in Mail and then try setting the account up again.
Assuming you are using IMAP to set up a Plusnet address then you need to follow:-
Mail > Preferences > + > Other Mail account.
Enter you Name, Email Address & Password. Then select 'Sign In'. You will get the message 'Unable to Verify Account Name or Password".
Enter your 'Username' and your Password should then automatically be filled in. Choose Account Type "IMAP" and then input 'imap.plus.net' for the Incoming Mail Server & "relay.plus.net" for the Outgoing Mail Server. Then 'Sign In'.
You will then get an error message "Password Could not be sent to 'relay.plus.net" securely". Click on 'Continue". The same message will appear again. Click on "Continue".
Select the Mail app to use with this account Select 'Done"
These settings work for me for both sending and receiving. I am using Mac OSX 10.11.2 El Capitan with Mail 9.2.
There is a lot to be said for not using an email address from an ISP and Plusnet's email accounts are not as secure as they should be. You might suggest to your Mum that she uses a different email service (Gmail, Hotmail etc) which should also be easier to set up in Mail.