msg_task_t task_message_chain_new(const char *issuer_hostname, const char *mailbox, const char* prev, const char *next);
msg_task_t task_message_data_new(const char *issuer_hostname, const char *mailbox, const char *block, unsigned int len);
msg_task_t task_message_end_data_new(const char *issuer_hostname, const char *mailbox);
msg_task_t task_message_chain_new(const char *issuer_hostname, const char *mailbox, const char* prev, const char *next);
msg_task_t task_message_data_new(const char *issuer_hostname, const char *mailbox, const char *block, unsigned int len);
msg_task_t task_message_end_data_new(const char *issuer_hostname, const char *mailbox);