From: Miquel van Smoorenburg <miquels@cistron.nl>
To: sendmail-bugs@sendmail.org
Subject: sendmail, relay_based_on_MX, and large # of MXes

mail from:<miquels@cistron.nl>250 <miquels@cistron.nl>... Sender okrcpt to:<user@bigfoot.com>
553 bftoemail2.bigfoot.com.:bftoemail6.bigfoot.com.:bftoemail20.bigfoot.com.:bftoemail8.bigfoot.com.:mai...ot.com.:bftoemail8.bigfoot.com.:bftoemail20.bigfoot.com.:bftoemail23.bigfoot.com.:orion.bigfoot.com.... Address too long

In parseaddr.c, prescan() stores the complete MX map expansion
in "pvpbuf". For sites with a lot of MX records like bigfoot
that buffer is too small.

The real fix is to rewrite the way map lookups are done (I think - I
don't know much about that part of sendmail internals), a quick fix
would be to expand the size of MAXNAME in config.h. Setting it to
512 (instead of 256) has fixed it for now.