Message from bogus Safe-mail address

All messages pretend to be sent from another Safe-mail.net user but actually are not from a Safe-mail.net user are clearly marked in the header of the message immediately below the From: line:
From: xxx@safe-mail.net
Warning: This message was NOT sent from Safe-mail.net user.

The Safe-mail.net system digitally signed each and every message. This signature could be generated only by the Safe-mail.net system but it could be verified by any email system before transferring it to the recipient. Unfortunately, this is mostly ignored.
However, the Safe-mail.net system checks this signature and marked it clearly as a message that was not sent from a user of Safe-mail.net. This is true for any address at Safe-mail.net including non-existing and even your own address.

In such case, the message you received is probably a fake one and you should ignore it. Please, do not read any such message unless expected.
Unfortunately we can't reject such messages automatically as there are systems that produce such messages. For example: you read an interesting article and would like to froward it to someone. Many system supply a button to do so and among the needed field one is your own email address. The correct way is to send it with "From:" of the REAL sender add a field "Apparently from:", but many systems do not do that.