Hi @Minkymoo ,
as stated on this chat this seems to be down to changes made by the email provider. Please remove your account form the phone Settings> Accounts and backup> Manage accounts> Select your email> Remove account. Then try to add this again from the same path: Settings> Accounts and backup> Manage accounts> Add account. When adding the account onto your device, select manual set up and select IMAP as the type of account, instead of POP3. Sign in to your email account on a PC / MAC or an internet browser to confirm that your account has not been disabled and that you are using the right credentials.
If 2-step verification was enabled for your account you may need to create an app specific password for accessing your email account on the Email app. If the IMAP protocol was disabled, you will need to log in on a web browser and enable this function. If this does not help, we would recommend contacting the email provider to get the right settings.