Thank you for your feedback.
I checked with a specialist and the sign & does not affect the normal function of your email address.
The reason you don't receive your email, aside from your mailbox is full or almost full, could be that you use the wrong user name and/or password.
Indeed, the Swisscom login password and the email password are two different things. The password of your Bluewin email address has been set up at his creation. You usually never use it then, except, for example in your case, to setup your email account on Outlook.
In case of doubt, you can change your Bluewin email account password on your Customer Center online. Simply go on Settings & Services > Email > Change Password > Forgotten password/change
Regarding the capacity of your mailbox, you got 5 GB per e-mail address. In the Webmail, click on "Settings" and then "Email", to show your current use on the top right.
Hope it helps,