E-mails going to the four winds.

[#1]

My partner logged into her e-mail account last night and found e-mails destined for me are going to her account, I also have 2 e-mail accounts for my two kids and me e-mails are going to them to, but none of their e-mails are going into my account, we have 4 e-mails addresses ending in .plus.com, but only mine are going to the others, can anyone offer me a solution to correct this please?
Thanks
Alan

[#2]

Are the emails going to incorrect mailboxes, or is it the email clients on your individual computers that are collecting mail from your mailbox as well as their own?
You can check if your personal email is going into the wrong mailbox by using webmail.