+/**
+ * Stating a policy about how to decrypt messages.
+ *
+ * See index.decrypt in notmuch-config(1) for more details.
+ */
+typedef enum {
+ NOTMUCH_DECRYPT_FALSE,
+ NOTMUCH_DECRYPT_TRUE,
+ NOTMUCH_DECRYPT_AUTO,
+ NOTMUCH_DECRYPT_NOSTASH,
+} notmuch_decryption_policy_t;
+
+/**
+ * Specify whether to decrypt encrypted parts while indexing.
+ *
+ * Be aware that the index is likely sufficient to reconstruct the
+ * cleartext of the message itself, so please ensure that the notmuch
+ * message index is adequately protected. DO NOT SET THIS FLAG TO TRUE
+ * without considering the security of your index.
+ *
+ * @since libnotmuch 5.1 (notmuch 0.26)
+ */
+notmuch_status_t
+notmuch_indexopts_set_decrypt_policy (notmuch_indexopts_t *indexopts,
+ notmuch_decryption_policy_t decrypt_policy);
+
+/**
+ * Return whether to decrypt encrypted parts while indexing.
+ * see notmuch_indexopts_set_decrypt_policy.
+ *
+ * @since libnotmuch 5.1 (notmuch 0.26)
+ */
+notmuch_decryption_policy_t
+notmuch_indexopts_get_decrypt_policy (const notmuch_indexopts_t *indexopts);
+