syntax = "proto2"; option go_package = "mail"; package appengine; message MailServiceError { enum ErrorCode { OK = 0; INTERNAL_ERROR = 1; BAD_REQUEST = 2; UNAUTHORIZED_SENDER = 3; INVALID_ATTACHMENT_TYPE = 4; INVALID_HEADER_NAME = 5; INVALID_CONTENT_ID = 6; } } message MailAttachment { required string FileName = 1; required bytes Data = 2; optional string ContentID = 3; } message MailHeader { required string name = 1; required string value = 2; } message MailMessage { required string Sender = 1; optional string ReplyTo = 2; repeated string To = 3; repeated string Cc = 4; repeated string Bcc = 5; required string Subject = 6; optional string TextBody = 7; optional string HtmlBody = 8; repeated MailAttachment Attachment = 9; repeated MailHeader Header = 10; }