MarpxPrivacy makes things private. You use your choice of other software to transmit your encrypted content to wherever you want it.
Email is a convenient method for sharing messages and small files. The content should be text wrapped during encryption. If an encrypted file's name finishes with ".enc.txt" it may arrive okay as an attachment. That's not a sure thing, since some email systems take it upon themselves to make changes to the content of attachments. If anything other that spaces and line ends are changed, even a single character, in a text-wrapped encrypted file, it will not decrypt correctly. Instead you will get a warning and no plain text result. The moral of this story: Test the email both ways between your confidant and yourself.
One alternative is to copy and paste the message or small file in its text-wrapped form directly into the body of an email. Include the <<< at the beginning and the >>> at the end. This generally transmits successfully. The downside: It demands skills of the recipient to copy and paste into the text area in the Decrypt Message page.
Encrypted text-wrapped messages can be pasted directly into social media. Let the whole world see it. But only your confidant (person or group) can get at the result. Rest assured that your social media provider will not put serious effort into breaking your code. We do not yet know of anyone who has broken a message where there are 3.5 trillion possible keys. Could the National Security Agency of the United States do that? Possibly; they aren't saying. On a visit to the NSA in November 2004, they told us that they have thirty percent of the computing power in the world. Would that be enough? Can't tell. But even for the NSA it could be dreadfully expensive to crack even one message.
Cloud based sharing
For files of any size, a better option is the use of cloud storage services that facilitate sharing.
Unless you are doing something that seriously threatens national security, you are likely quite safe to put your messages in public places. That's not a guarantee; that's a simple statement about the effects of huge numbers. Of course, if you post codes on sticky notes or click on unfamiliar Internet links, or give scraps of information to strangers, all bets are off. Per the old Hill Street Blues line, "Be careful out there!" Cranial cramps void all attempts at privacy!
What to do if you want even greater security? In the United States, there are Extreme Encryption upgrade files, for sale at https://BuyExtremeEncryption.com. Alternatively, you can use manual keys to encrypt an encrypted message or file a second time and even more times. It works. Your recipient will need the manual keys to use them in reverse order to retrieve the original plain text.
Archive for your own use
Store your files in the cloud or on your PC. One strong proviso: Be sure that you have high quality security system on your device that blocks intruders and especially keystroke monitoring. Archiving for your own use is easiest if you use the Automatic Keys option and use a roster entry that is for yourself alone (not shared with another confidant).