1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * %sccs.include.redist.c%
7  */
8 
9 #ifndef lint
10 static char sccsid[] = "@(#)savemail.c	8.15 (Berkeley) 10/17/93";
11 #endif /* not lint */
12 
13 # include "sendmail.h"
14 # include <pwd.h>
15 
16 /*
17 **  SAVEMAIL -- Save mail on error
18 **
19 **	If mailing back errors, mail it back to the originator
20 **	together with an error message; otherwise, just put it in
21 **	dead.letter in the user's home directory (if he exists on
22 **	this machine).
23 **
24 **	Parameters:
25 **		e -- the envelope containing the message in error.
26 **
27 **	Returns:
28 **		none
29 **
30 **	Side Effects:
31 **		Saves the letter, by writing or mailing it back to the
32 **		sender, or by putting it in dead.letter in her home
33 **		directory.
34 */
35 
36 /* defines for state machine */
37 # define ESM_REPORT	0	/* report to sender's terminal */
38 # define ESM_MAIL	1	/* mail back to sender */
39 # define ESM_QUIET	2	/* messages have already been returned */
40 # define ESM_DEADLETTER	3	/* save in ~/dead.letter */
41 # define ESM_POSTMASTER	4	/* return to postmaster */
42 # define ESM_USRTMP	5	/* save in /usr/tmp/dead.letter */
43 # define ESM_PANIC	6	/* leave the locked queue/transcript files */
44 # define ESM_DONE	7	/* the message is successfully delivered */
45 
46 
47 savemail(e)
48 	register ENVELOPE *e;
49 {
50 	register struct passwd *pw;
51 	register FILE *fp;
52 	int state;
53 	auto ADDRESS *q = NULL;
54 	char buf[MAXLINE+1];
55 	extern struct passwd *getpwnam();
56 	register char *p;
57 	extern char *ttypath();
58 	typedef int (*fnptr)();
59 
60 	if (tTd(6, 1))
61 	{
62 		printf("\nsavemail, errormode = %c, id = %s\n  e_from=",
63 			e->e_errormode, e->e_id == NULL ? "NONE" : e->e_id);
64 		printaddr(&e->e_from, FALSE);
65 	}
66 
67 	if (e->e_id == NULL)
68 	{
69 		/* can't return a message with no id */
70 		return;
71 	}
72 
73 	/*
74 	**  In the unhappy event we don't know who to return the mail
75 	**  to, make someone up.
76 	*/
77 
78 	if (e->e_from.q_paddr == NULL)
79 	{
80 		e->e_sender = "Postmaster";
81 		if (parseaddr(e->e_sender, &e->e_from,
82 			      RF_COPYPARSE|RF_SENDERADDR, '\0', NULL, e) == NULL)
83 		{
84 			syserr("553 Cannot parse Postmaster!");
85 			ExitStat = EX_SOFTWARE;
86 			finis();
87 		}
88 	}
89 	e->e_to = NULL;
90 
91 	/*
92 	**  Basic state machine.
93 	**
94 	**	This machine runs through the following states:
95 	**
96 	**	ESM_QUIET	Errors have already been printed iff the
97 	**			sender is local.
98 	**	ESM_REPORT	Report directly to the sender's terminal.
99 	**	ESM_MAIL	Mail response to the sender.
100 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
101 	**	ESM_POSTMASTER	Mail response to the postmaster.
102 	**	ESM_PANIC	Save response anywhere possible.
103 	*/
104 
105 	/* determine starting state */
106 	switch (e->e_errormode)
107 	{
108 	  case EM_WRITE:
109 		state = ESM_REPORT;
110 		break;
111 
112 	  case EM_BERKNET:
113 		/* mail back, but return o.k. exit status */
114 		ExitStat = EX_OK;
115 
116 		/* fall through.... */
117 
118 	  case EM_MAIL:
119 		state = ESM_MAIL;
120 		break;
121 
122 	  case EM_PRINT:
123 	  case '\0':
124 		state = ESM_QUIET;
125 		break;
126 
127 	  case EM_QUIET:
128 		/* no need to return anything at all */
129 		return;
130 
131 	  default:
132 		syserr("554 savemail: bogus errormode x%x\n", e->e_errormode);
133 		state = ESM_MAIL;
134 		break;
135 	}
136 
137 	/* if this is already an error response, send to postmaster */
138 	if (bitset(EF_RESPONSE, e->e_flags))
139 	{
140 		if (e->e_parent != NULL &&
141 		    bitset(EF_RESPONSE, e->e_parent->e_flags))
142 		{
143 			/* got an error sending a response -- can it */
144 			return;
145 		}
146 		state = ESM_POSTMASTER;
147 	}
148 
149 	while (state != ESM_DONE)
150 	{
151 		if (tTd(6, 5))
152 			printf("  state %d\n", state);
153 
154 		switch (state)
155 		{
156 		  case ESM_QUIET:
157 			if (e->e_from.q_mailer == LocalMailer)
158 				state = ESM_DEADLETTER;
159 			else
160 				state = ESM_MAIL;
161 			break;
162 
163 		  case ESM_REPORT:
164 
165 			/*
166 			**  If the user is still logged in on the same terminal,
167 			**  then write the error messages back to hir (sic).
168 			*/
169 
170 			p = ttypath();
171 			if (p == NULL || freopen(p, "w", stdout) == NULL)
172 			{
173 				state = ESM_MAIL;
174 				break;
175 			}
176 
177 			expand("\201n", buf, &buf[sizeof buf - 1], e);
178 			printf("\r\nMessage from %s...\r\n", buf);
179 			printf("Errors occurred while sending mail.\r\n");
180 			if (e->e_xfp != NULL)
181 			{
182 				(void) fflush(e->e_xfp);
183 				fp = fopen(queuename(e, 'x'), "r");
184 			}
185 			else
186 				fp = NULL;
187 			if (fp == NULL)
188 			{
189 				syserr("Cannot open %s", queuename(e, 'x'));
190 				printf("Transcript of session is unavailable.\r\n");
191 			}
192 			else
193 			{
194 				printf("Transcript follows:\r\n");
195 				while (fgets(buf, sizeof buf, fp) != NULL &&
196 				       !ferror(stdout))
197 					fputs(buf, stdout);
198 				(void) xfclose(fp, "savemail transcript", e->e_id);
199 			}
200 			printf("Original message will be saved in dead.letter.\r\n");
201 			state = ESM_DEADLETTER;
202 			break;
203 
204 		  case ESM_MAIL:
205 			/*
206 			**  If mailing back, do it.
207 			**	Throw away all further output.  Don't alias,
208 			**	since this could cause loops, e.g., if joe
209 			**	mails to joe@x, and for some reason the network
210 			**	for @x is down, then the response gets sent to
211 			**	joe@x, which gives a response, etc.  Also force
212 			**	the mail to be delivered even if a version of
213 			**	it has already been sent to the sender.
214 			**
215 			**  If this is a configuration or local software
216 			**	error, send to the local postmaster as well,
217 			**	since the originator can't do anything
218 			**	about it anyway.  Note that this is a full
219 			**	copy of the message (intentionally) so that
220 			**	the Postmaster can forward things along.
221 			*/
222 
223 			if (ExitStat == EX_CONFIG || ExitStat == EX_SOFTWARE)
224 			{
225 				(void) sendtolist("postmaster",
226 					  NULLADDR, &e->e_errorqueue, e);
227 			}
228 			if (strcmp(e->e_from.q_paddr, "<>") != 0)
229 			{
230 				(void) sendtolist(e->e_from.q_paddr,
231 					  NULLADDR, &e->e_errorqueue, e);
232 			}
233 
234 			/*
235 			**  Deliver a non-delivery report to the
236 			**  Postmaster-designate (not necessarily
237 			**  Postmaster).  This does not include the
238 			**  body of the message, for privacy reasons.
239 			**  You really shouldn't need this.
240 			*/
241 
242 			e->e_flags |= EF_PM_NOTIFY;
243 
244 			q = e->e_errorqueue;
245 			if (q == NULL)
246 			{
247 				/* this is an error-error */
248 				state = ESM_POSTMASTER;
249 				break;
250 			}
251 			if (returntosender(e->e_message,
252 					   q, (e->e_class >= 0), e) == 0)
253 			{
254 				state = ESM_DONE;
255 				break;
256 			}
257 
258 			/* didn't work -- return to postmaster */
259 			state = ESM_POSTMASTER;
260 			break;
261 
262 		  case ESM_POSTMASTER:
263 			/*
264 			**  Similar to previous case, but to system postmaster.
265 			*/
266 
267 			q = NULL;
268 			if (sendtolist("postmaster", NULL, &q, e) <= 0)
269 			{
270 				syserr("553 cannot parse postmaster!");
271 				ExitStat = EX_SOFTWARE;
272 				state = ESM_USRTMP;
273 				break;
274 			}
275 			if (returntosender(e->e_message,
276 					   q, (e->e_class >= 0), e) == 0)
277 			{
278 				state = ESM_DONE;
279 				break;
280 			}
281 
282 			/* didn't work -- last resort */
283 			state = ESM_USRTMP;
284 			break;
285 
286 		  case ESM_DEADLETTER:
287 			/*
288 			**  Save the message in dead.letter.
289 			**	If we weren't mailing back, and the user is
290 			**	local, we should save the message in
291 			**	~/dead.letter so that the poor person doesn't
292 			**	have to type it over again -- and we all know
293 			**	what poor typists UNIX users are.
294 			*/
295 
296 			p = NULL;
297 			if (e->e_from.q_mailer == LocalMailer)
298 			{
299 				if (e->e_from.q_home != NULL)
300 					p = e->e_from.q_home;
301 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
302 					p = pw->pw_dir;
303 			}
304 			if (p == NULL)
305 			{
306 				/* no local directory */
307 				state = ESM_MAIL;
308 				break;
309 			}
310 			if (e->e_dfp != NULL)
311 			{
312 				bool oldverb = Verbose;
313 
314 				/* we have a home directory; open dead.letter */
315 				define('z', p, e);
316 				expand("\201z/dead.letter", buf, &buf[sizeof buf - 1], e);
317 				Verbose = TRUE;
318 				message("Saving message in %s", buf);
319 				Verbose = oldverb;
320 				e->e_to = buf;
321 				q = NULL;
322 				(void) sendtolist(buf, &e->e_from, &q, e);
323 				if (q != NULL &&
324 				    !bitset(QBADADDR, q->q_flags) &&
325 				    deliver(e, q) == 0)
326 					state = ESM_DONE;
327 				else
328 					state = ESM_MAIL;
329 			}
330 			else
331 			{
332 				/* no data file -- try mailing back */
333 				state = ESM_MAIL;
334 			}
335 			break;
336 
337 		  case ESM_USRTMP:
338 			/*
339 			**  Log the mail in /usr/tmp/dead.letter.
340 			*/
341 
342 			if (e->e_class < 0)
343 			{
344 				state = ESM_DONE;
345 				break;
346 			}
347 
348 			fp = dfopen("/usr/tmp/dead.letter",
349 				    O_WRONLY|O_CREAT|O_APPEND, FileMode);
350 			if (fp == NULL)
351 			{
352 				state = ESM_PANIC;
353 				break;
354 			}
355 
356 			putfromline(fp, FileMailer, e);
357 			(*e->e_puthdr)(fp, FileMailer, e);
358 			putline("\n", fp, FileMailer);
359 			(*e->e_putbody)(fp, FileMailer, e, NULL);
360 			putline("\n", fp, FileMailer);
361 			(void) fflush(fp);
362 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
363 			(void) xfclose(fp, "savemail", "/usr/tmp/dead.letter");
364 			break;
365 
366 		  default:
367 			syserr("554 savemail: unknown state %d", state);
368 
369 			/* fall through ... */
370 
371 		  case ESM_PANIC:
372 			/* leave the locked queue & transcript files around */
373 			syserr("554 savemail: cannot save rejected email anywhere");
374 			exit(EX_SOFTWARE);
375 		}
376 	}
377 }
378 /*
379 **  RETURNTOSENDER -- return a message to the sender with an error.
380 **
381 **	Parameters:
382 **		msg -- the explanatory message.
383 **		returnq -- the queue of people to send the message to.
384 **		sendbody -- if TRUE, also send back the body of the
385 **			message; otherwise just send the header.
386 **		e -- the current envelope.
387 **
388 **	Returns:
389 **		zero -- if everything went ok.
390 **		else -- some error.
391 **
392 **	Side Effects:
393 **		Returns the current message to the sender via
394 **		mail.
395 */
396 
397 static bool	SendBody;
398 
399 #define MAXRETURNS	6	/* max depth of returning messages */
400 #define ERRORFUDGE	100	/* nominal size of error message text */
401 
402 returntosender(msg, returnq, sendbody, e)
403 	char *msg;
404 	ADDRESS *returnq;
405 	bool sendbody;
406 	register ENVELOPE *e;
407 {
408 	char buf[MAXNAME];
409 	extern putheader(), errbody();
410 	register ENVELOPE *ee;
411 	ENVELOPE *oldcur = CurEnv;
412 	ENVELOPE errenvelope;
413 	static int returndepth;
414 	register ADDRESS *q;
415 
416 	if (returnq == NULL)
417 		return (-1);
418 
419 	if (msg == NULL)
420 		msg = "Unable to deliver mail";
421 
422 	if (tTd(6, 1))
423 	{
424 		printf("Return To Sender: msg=\"%s\", depth=%d, e=%x, returnq=",
425 		       msg, returndepth, e);
426 		printaddr(returnq, TRUE);
427 	}
428 
429 	if (++returndepth >= MAXRETURNS)
430 	{
431 		if (returndepth != MAXRETURNS)
432 			syserr("554 returntosender: infinite recursion on %s", returnq->q_paddr);
433 		/* don't "unrecurse" and fake a clean exit */
434 		/* returndepth--; */
435 		return (0);
436 	}
437 
438 	SendBody = sendbody;
439 	define('g', e->e_from.q_paddr, e);
440 	ee = newenvelope(&errenvelope, e);
441 	define('a', "\201b", ee);
442 	define('r', "internal", ee);
443 	define('s', "localhost", ee);
444 	define('_', "localhost", ee);
445 	ee->e_puthdr = putheader;
446 	ee->e_putbody = errbody;
447 	ee->e_flags |= EF_RESPONSE|EF_METOO;
448 	if (!bitset(EF_OLDSTYLE, e->e_flags))
449 		ee->e_flags &= ~EF_OLDSTYLE;
450 	ee->e_sendqueue = returnq;
451 	ee->e_msgsize = ERRORFUDGE;
452 	if (!NoReturn)
453 		ee->e_msgsize += e->e_msgsize;
454 	openxscript(ee);
455 	for (q = returnq; q != NULL; q = q->q_next)
456 	{
457 		if (bitset(QBADADDR, q->q_flags))
458 			continue;
459 
460 		if (!bitset(QDONTSEND, q->q_flags))
461 			ee->e_nrcpts++;
462 
463 		if (!DontPruneRoutes && pruneroute(q->q_paddr))
464 			parseaddr(q->q_paddr, q, RF_COPYPARSE, '\0', NULL, e);
465 
466 		if (q->q_alias == NULL)
467 			addheader("To", q->q_paddr, ee);
468 	}
469 
470 # ifdef LOG
471 	if (LogLevel > 5)
472 		syslog(LOG_INFO, "%s: %s: return to sender: %s",
473 			e->e_id, ee->e_id, msg);
474 # endif
475 
476 	(void) sprintf(buf, "Returned mail: %s", msg);
477 	addheader("Subject", buf, ee);
478 	if (SendMIMEErrors)
479 	{
480 		addheader("MIME-Version", "1.0", ee);
481 		(void) sprintf(buf, "%s.%ld/%s",
482 			ee->e_id, curtime(), MyHostName);
483 		ee->e_msgboundary = newstr(buf);
484 		(void) sprintf(buf, "multipart/mixed; boundary=\"%s\"",
485 					ee->e_msgboundary);
486 		addheader("Content-Type", buf, ee);
487 	}
488 
489 	/* fake up an address header for the from person */
490 	expand("\201n", buf, &buf[sizeof buf - 1], e);
491 	if (parseaddr(buf, &ee->e_from, RF_COPYALL|RF_SENDERADDR, '\0', NULL, e) == NULL)
492 	{
493 		syserr("553 Can't parse myself!");
494 		ExitStat = EX_SOFTWARE;
495 		returndepth--;
496 		return (-1);
497 	}
498 	ee->e_sender = ee->e_from.q_paddr;
499 
500 	/* push state into submessage */
501 	CurEnv = ee;
502 	define('f', "\201n", ee);
503 	define('x', "Mail Delivery Subsystem", ee);
504 	eatheader(ee, TRUE);
505 
506 	/* mark statistics */
507 	markstats(ee, NULLADDR);
508 
509 	/* actually deliver the error message */
510 	sendall(ee, SM_DEFAULT);
511 
512 	/* restore state */
513 	dropenvelope(ee);
514 	CurEnv = oldcur;
515 	returndepth--;
516 
517 	/* should check for delivery errors here */
518 	return (0);
519 }
520 /*
521 **  ERRBODY -- output the body of an error message.
522 **
523 **	Typically this is a copy of the transcript plus a copy of the
524 **	original offending message.
525 **
526 **	Parameters:
527 **		fp -- the output file.
528 **		m -- the mailer to output to.
529 **		e -- the envelope we are working in.
530 **
531 **	Returns:
532 **		none
533 **
534 **	Side Effects:
535 **		Outputs the body of an error message.
536 */
537 
538 errbody(fp, m, e)
539 	register FILE *fp;
540 	register struct mailer *m;
541 	register ENVELOPE *e;
542 {
543 	register FILE *xfile;
544 	char *p;
545 	register ADDRESS *q;
546 	bool printheader;
547 	char buf[MAXLINE];
548 
549 	if (e->e_parent == NULL)
550 	{
551 		syserr("errbody: null parent");
552 		putline("   ----- Original message lost -----\n", fp, m);
553 		return;
554 	}
555 
556 	/*
557 	**  Output MIME header.
558 	*/
559 
560 	if (e->e_msgboundary != NULL)
561 	{
562 		putline("This is a MIME-encapsulated message", fp, m);
563 		putline("", fp, m);
564 		(void) sprintf(buf, "--%s", e->e_msgboundary);
565 		putline(buf, fp, m);
566 		putline("", fp, m);
567 	}
568 
569 	/*
570 	**  Output introductory information.
571 	*/
572 
573 	for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
574 		if (bitset(QBADADDR, q->q_flags))
575 			break;
576 	if (q == NULL && !bitset(EF_FATALERRS, e->e_parent->e_flags))
577 	{
578 		putline("    **********************************************",
579 			fp, m);
580 		putline("    **      THIS IS A WARNING MESSAGE ONLY      **",
581 			fp, m);
582 		putline("    **  YOU DO NOT NEED TO RESEND YOUR MESSAGE  **",
583 			fp, m);
584 		putline("    **********************************************",
585 			fp, m);
586 		putline("", fp, m);
587 	}
588 	sprintf(buf, "The original message was received at %s",
589 		arpadate(ctime(&e->e_parent->e_ctime)));
590 	putline(buf, fp, m);
591 	expand("from \201_", buf, &buf[sizeof buf - 1], e->e_parent);
592 	putline(buf, fp, m);
593 	putline("", fp, m);
594 
595 	/*
596 	**  Output error message header (if specified and available).
597 	*/
598 
599 	if (ErrMsgFile != NULL)
600 	{
601 		if (*ErrMsgFile == '/')
602 		{
603 			xfile = fopen(ErrMsgFile, "r");
604 			if (xfile != NULL)
605 			{
606 				while (fgets(buf, sizeof buf, xfile) != NULL)
607 				{
608 					expand(buf, buf, &buf[sizeof buf - 1], e);
609 					putline(buf, fp, m);
610 				}
611 				(void) fclose(xfile);
612 				putline("\n", fp, m);
613 			}
614 		}
615 		else
616 		{
617 			expand(ErrMsgFile, buf, &buf[sizeof buf - 1], e);
618 			putline(buf, fp, m);
619 			putline("", fp, m);
620 		}
621 	}
622 
623 	/*
624 	**  Output message introduction
625 	*/
626 
627 	printheader = TRUE;
628 	for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
629 	{
630 		if (bitset(QBADADDR|QREPORT, q->q_flags))
631 		{
632 			if (printheader)
633 			{
634 				putline("   ----- The following addresses had delivery problems -----",
635 					fp, m);
636 				printheader = FALSE;
637 			}
638 			strcpy(buf, q->q_paddr);
639 			if (bitset(QBADADDR, q->q_flags))
640 				strcat(buf, "  (unrecoverable error)");
641 			else
642 				strcat(buf, "  (transient failure)");
643 			putline(buf, fp, m);
644 			if (q->q_alias != NULL)
645 			{
646 				strcpy(buf, "    (expanded from: ");
647 				strcat(buf, q->q_alias->q_paddr);
648 				strcat(buf, ")");
649 				putline(buf, fp, m);
650 			}
651 		}
652 	}
653 	if (!printheader)
654 		putline("\n", fp, m);
655 
656 	/*
657 	**  Output transcript of errors
658 	*/
659 
660 	(void) fflush(stdout);
661 	p = queuename(e->e_parent, 'x');
662 	if ((xfile = fopen(p, "r")) == NULL)
663 	{
664 		syserr("Cannot open %s", p);
665 		putline("   ----- Transcript of session is unavailable -----\n", fp, m);
666 	}
667 	else
668 	{
669 		putline("   ----- Transcript of session follows -----\n", fp, m);
670 		if (e->e_xfp != NULL)
671 			(void) fflush(e->e_xfp);
672 		while (fgets(buf, sizeof buf, xfile) != NULL)
673 			putline(buf, fp, m);
674 		(void) xfclose(xfile, "errbody xscript", p);
675 	}
676 	errno = 0;
677 
678 	/*
679 	**  Output text of original message
680 	*/
681 
682 	if (NoReturn)
683 		SendBody = FALSE;
684 	putline("", fp, m);
685 	if (e->e_parent->e_df != NULL)
686 	{
687 		if (SendBody)
688 			putline("   ----- Original message follows -----\n", fp, m);
689 		else
690 			putline("   ----- Message header follows -----\n", fp, m);
691 		(void) fflush(fp);
692 
693 		if (e->e_msgboundary != NULL)
694 		{
695 			putline("", fp, m);
696 			(void) sprintf(buf, "--%s", e->e_msgboundary);
697 			putline(buf, fp, m);
698 			putline("Content-Type: message/rfc822", fp, m);
699 			putline("", fp, m);
700 		}
701 		putheader(fp, m, e->e_parent);
702 		putline("", fp, m);
703 		if (SendBody)
704 			putbody(fp, m, e->e_parent, e->e_msgboundary);
705 		else
706 			putline("   ----- Message body suppressed -----", fp, m);
707 	}
708 	else
709 	{
710 		putline("  ----- No message was collected -----\n", fp, m);
711 	}
712 
713 	if (e->e_msgboundary != NULL)
714 	{
715 		putline("", fp, m);
716 		(void) sprintf(buf, "--%s--", e->e_msgboundary);
717 		putline(buf, fp, m);
718 	}
719 	putline("", fp, m);
720 
721 	/*
722 	**  Cleanup and exit
723 	*/
724 
725 	if (errno != 0)
726 		syserr("errbody: I/O error");
727 }
728 /*
729 **  PRUNEROUTE -- prune an RFC-822 source route
730 **
731 **	Trims down a source route to the last internet-registered hop.
732 **	This is encouraged by RFC 1123 section 5.3.3.
733 **
734 **	Parameters:
735 **		addr -- the address
736 **
737 **	Returns:
738 **		TRUE -- address was modified
739 **		FALSE -- address could not be pruned
740 **
741 **	Side Effects:
742 **		modifies addr in-place
743 */
744 
745 pruneroute(addr)
746 	char *addr;
747 {
748 #ifdef NAMED_BIND
749 	char *start, *at, *comma;
750 	char c;
751 	int rcode;
752 	char hostbuf[BUFSIZ];
753 	char *mxhosts[MAXMXHOSTS + 1];
754 
755 	/* check to see if this is really a route-addr */
756 	if (*addr != '<' || addr[1] != '@' || addr[strlen(addr) - 1] != '>')
757 		return FALSE;
758 	start = strchr(addr, ':');
759 	at = strrchr(addr, '@');
760 	if (start == NULL || at == NULL || at < start)
761 		return FALSE;
762 
763 	/* slice off the angle brackets */
764 	strcpy(hostbuf, at + 1);
765 	hostbuf[strlen(hostbuf) - 1] = '\0';
766 
767 	while (start)
768 	{
769 		if (getmxrr(hostbuf, mxhosts, FALSE, &rcode) > 0)
770 		{
771 			strcpy(addr + 1, start + 1);
772 			return TRUE;
773 		}
774 		c = *start;
775 		*start = '\0';
776 		comma = strrchr(addr, ',');
777 		if (comma && comma[1] == '@')
778 			strcpy(hostbuf, comma + 2);
779 		else
780 			comma = 0;
781 		*start = c;
782 		start = comma;
783 	}
784 #endif
785 	return FALSE;
786 }
787