rewriter smtp_request%(is_orig: bool, command: string, arg: string%)
	%{
	if ( command->Len() > 0 )
		{
		u_char ch = command->Bytes()[0];

		if ( isalpha(ch) )
			{ // Do not dump artificial commands: ">", ".", "***"
			@WRITE@(is_orig, command->AsString());
			@WRITE@(is_orig, 1, " ");
			}
		}

	@WRITE@(is_orig, arg->AsString());
	@WRITE@(is_orig, 2, "\r\n");
	%}

rewriter smtp_reply%(is_orig: bool, code: count, msg: string, cont_resp: bool%)
	%{
	const char* str = fmt("%lu", (unsigned long) code);
	int len = strlen(str);

	@WRITE@(is_orig, len, str);

	if ( cont_resp )
		@WRITE@(is_orig, "-");
	else
		@WRITE@(is_orig, " ");

	@WRITE@(is_orig, msg->AsString());
	@WRITE@(is_orig, "\r\n");
	%}

# Since SMTP data is delivered by lines ending with CRLF, this
# function takes a line without the trailing CRLF and dumps the string
# followed by CRLF. If you want to dump multiple lines, please dump
# them one at a time (without trailing CRLF's).
rewriter smtp_data%(is_orig: bool, data: string%)
	%{
	if ( data->Len() > 0 && data->Bytes()[0] == '.')
		@WRITE@(is_orig, ".");

	@WRITE@(is_orig, data->AsString());
	@WRITE@(is_orig, "\r\n");
	%}