Sendmail 8.13.3 Programmer's Guide

Milter APIs
Data Access APIs
Chapter 224
xcode Specifies the extended reply code as specified in RFC
1893 (Enhanced Mail System Status Codes) or 2034
(SMTP Service Extension for Returning Enhanced
Error Codes). If xcode is NULL, an extended code is
not used; otherwise, xcode must conform to RFC 1893
or RFC 2034.
... Specifies the remaining arguments, that are single
lines of text (upto 32 arguments), which is used as the
text part of the SMTP reply. The list must be NULL
terminated.
Return Values
smfi_setmlreply() fails because of the following reasons and returns
MI_FAILURE:
• The rcode or xcode argument is invalid.
• A memory-allocation failure occurs.
• A text line contains a carriage return (CR) or line feed (LF).
• The length of any text is more than the MAXREPLYLEN (980) value.
• The reply contains more than 32 lines of text.
smfi_setmlreply() returns MI_SUCCESS on success.