@type t() :: %OpenXchangeClient.Model.MailComposeMessageModel{
attachments: [OpenXchangeClient.Model.Attachment.t()] | nil,
bcc: [[String.t()]] | nil,
cc: [[String.t()]] | nil,
content: String.t() | nil,
contentType: String.t() | nil,
from: [String.t()] | nil,
id: String.t() | nil,
meta: OpenXchangeClient.Model.Meta.t() | nil,
priority: String.t() | nil,
requestReadReceipt: boolean() | nil,
security: OpenXchangeClient.Model.Security.t() | nil,
sharedAttachments: OpenXchangeClient.Model.SharedAttachments.t() | nil,
subject: String.t() | nil,
to: [[String.t()]] | nil
}