You wish to increase your storage space for your files and e-mails? This is done very easily.
Log in to your mailbox.org Office and go to the Settings page (the round icon with your initiales at top right, then choose "settings"):
Select the first item, ‘mailbox.org,’ to open the mailbox.org user data section (This is usually preselected and not numbered in the picture).
Under ‘Contract and Fees’, you can quickly and easily select another package. You can switch to a different package at any time. When you switch to a less expensive package, the fee difference will be credited to your balance.
Just move the sliders (4) to the desired storage capacities. The upper one sets the mail storage, the lower one is for the cloud storage capacity. Click aon "Save", when done.
It might be nessessary to log out and in again.
After you have selected a new package, the old package is billed instantly and the remainder of the fee is credited to your balance. For example, if you paid €1 and used the MAIL package for just two weeks, you will be charged €0.50 and receive the remainder as credit.
To see how much storage space is left, have a look at the widget "Quota".