You should only select the Allow SHA-1 globally option if your organization communicates using the SHA-1 cryptographic hash function for S/MIME message security and you want these communications to appear as trusted.
A list of mime types, separated by semicolon. This can be used to limit the usage of this entity to files with matching mime types. Use the wizard button on the right to get a list of existing file types to choose from, using it will fill in the file masks as well
You set up a content compliance, attachment compliance, objectionable content, or routing rule to require hosted S/MIME encryption using the Modify message action’s Encryption (onward delivery only) options.
This fatal error can be caused by a VAST response that declares unsupported MIME types for all available MediaFiles (for example, Flash on mobile, or WebM on iOS).
You have requested that messages be encrypted to yourself, but the currently selected identity does not define an (OpenPGP or S/MIME) encryption key to use for this. Please select the key(s) to use in the identity configuration
KIO can also locate handlers for specified MIME types; these handlers can then be embedded within the requesting application using the KParts technology.