Can I upgrade? How much should I pay?
You
can upgrade from trial or another subscription by purchasing a new
subscription for the same domain name, then by transferring all
emails accounts over to the new subscription.
All
calendar, contacts, infostore data will be accessible after the
transfer.
Please
notice that it
is not possible to purchase the subscription of the same type for the
same domain name. Instead
you can
purchase as
many
additional mailboxes as
you need
without account upgrade.
This is useful when you are not willing to pay for
additional functions provided with higher packages and only need more
mailboxes.
Pricing depends on package as the higher the package the more options
you get with it.
An option for adding additional mailboxes can be found on main page of OX subscription.
Open-Xchange User Guide can be found here