Describe the bug
Email content from some senders are parsed as file attachment. In this case email body is empty and email has 2 file attachments with no name. One is for text body, another is for html body.

Expected behavior
Mail body should be parsed correctly.

Screenshots
Here is the data of the mail that causes this issue:
mail-data.txt

Desktop / Server (please complete the following information):

• OS: Ubuntu 19.04
• PHP: 7.3
• Version. Package version is 2.5.0

Additional context
Some emails are parsed correctly.