jbruecher What field do I have to change to increase the size to 256 chars?
Emails should already limited to 255 characters.
To make sure use your favorite DB editor and:
Go look at your ost_user_email
table. Ensure that the address
field is varchar(255).
Go look at your ost_staff
table. Ensure that the email
field is varchar(255).
Go look at your ost_form_field
table. Ensure that name=email in the configuration column that length is set to 255.
Always make sure that you take a backup of your database PRIOR to making changes.