A few questions please

Hi Folks,

I am leaning towards Mailbox.org but a bit confused on a few things and hoping you could shed some light on these:

1. If I don't enable the Guard/Encrypted Mailbox will all my mailbox still be zero knowledge (that is - impossible to read/access by Mailbox team)?

2. What about photos and documents on the Mailbox cloud? Lets say if I upload a photo or an Excel file to the cloud, will it also be zero knowledge without Guard/Secure Mailbox enabled?

3. I understand calendar and contact sync is unencrypted due to some limitations.

I don't use calendar at all, so no issues with this.

For contacts, if I create a contact in my web mail, will it be unencrypted and visible to 3rd parties / Mailbox.org?

I only use web client, Thunderbird and Fairmail on my phone. None of these is syncing contacts but rather have their own database locally.

4. Spam filter: some email providers, for example, Posteo, simply block legitimate emails without delivering to user if they think these contain spam. Will Mailbox still deliver to me so that I could decide what to do with the email?

Thanks a lot and sorry for so many questions.