I have now finished programming a new back end for the donations. So far, I always manually inserted donations into the database. Since this required always some time and a proper browser, I know have a much easier and faster process that also automatically sends a thank-you email to the user, instead of me having to do a lot of manual input and email writing.
While this will be a little less personal, it will however speed up the process and make sure that donations are activated much sooner than so far the case, even when I am on a trip. Thanks again to all donators, all those are a great motivation to me to keep the server up and running!