Cannot access the correct email account.

[#1]

Hi All,
I'm trying to fix an email problem for a family member. Here is the problem: the email address in the webmail app is different to the email address given. "example1@username.plus.com" is the default and "example2@username.plus.com" is the given. Both addresses exist and work but I cannot access the "example2" inbox.
Is they're a way to access the 2nd address or make it the default address? Any help will be appreciated.
Thanks in advance

[#2]

Can you confirm that you are entering the webmail login Username as "username+example2"?

[#3]

Just tried "username+example2" and got "Login Failed".

[#4]

... and you are using the password set up for the mailbox (not the main account password)?

[#5]

I was only given the account password which lets me access webmail with the account username but not the "example2@username.plus.com" webmail.

[#6]

I just emailed "example2@username.plus.com" and it doesn't exist. I think my Grandma has given me some incorrect information. LOL I'll have to get the right information.
Thanks for the help so far.

[#7]

You need to go to http://email.plus.net/ to view/edit the mailboxes on her account.