Specifies if the disposition described by the disposition type was a result of an manual or automatic action. You can use static fields of this class: ManualAction, AutomaticAction.

Specifies if the Message Delivery Notification (MDN) was sent manually or automatically. You can use static fields of this class: SentManually, SentAutomatically.

Describes disposition type of the message. You can use static fields of this class: Displayed, Deleted.

Indicates the action performed by the Reporting-MTA as a result of its attempt to deliver the message. You can use static fields of this class: Failed, Delayed, Delivered, Relayed, Expanded.

Types of actions which mail user agent should take to present the specified data to the user. It simply says what you should do with the data. (RFC 2183) You can use static fields of this class: Inline, Attachment.

Mime encoding format. You can use static fields of this class: Bit7, Bit8, QuotedPrintable, Base64.

Importance of email message. You can use static fields of this class: High, Normal, Low.

Priority of email message. You can use static fields of this class: Urgent, Normal, NonUrgent.

Represents report type. You can use static fields of this class: DeliveryStatus, DispositionNotification.

Sensitivity of email message. You can use static fields of this class e.g. Personal, Private, CompanyConfidential.

Represents content's subtype (RFC 2045).

Represents content's type (RFC 2045).

Header encoding format.