Do I really need an MX record? (for e-mail to work)

[sm5w2 at hotmail.com]

rick pim wrote:

>  > Because of all three of the above (especially item 3) I think I'll be
>  > letting this experiment go a while longer and see if not having an MX
>  > record turns out to be a great way to prevent spam from finding us.
>
> unfortunately, my experience with spam proxies is that they seem
> to find MX records just fine.

Um, my situation is that there is no MX record for my domain.  I'm
trying to say that having no MX record is actually great, because legit
e-mail is still getting to us, while the average of 50 spams per day
from zombie-relays has turned into a trickle of maybe 5.

> in addition, we have had a number of complaints over the years from
> remote sites that cannot send mail to addresses that don't have MX
> records. this represents broken software, but it's not necessarily
> easy to convince irate folks of that.

I went to DNSstuff.com and did an ISP-lookup of our MX record.  What I
get back is a list of a few dozen ISP's and the results of their
attempts to look up our MX record.  Most of the responses is "No cache
answer:  Would go to NS of com (or .root)".  I take that to means that
they would look at the A record.

But yes, we run the risk of not getting e-mail from some organization
who's outgoing server does not look for the A record when it finds no
MX record.

> IMHO, the bottom line is that going MX-less is unlikely to have a
> significant effect on spam volume

My experience is proving to be just the opposite.

Over the past 7 years, our server has had a properly-configured MX
record, and has had the same IP address for that entire time (we had a
net-block of 64 IP's).  We have a few "well-known" e-mail addresses
(like "sales" and "support") which in 2004 received 26,000 spams (and
about 16,000 so far this year).  That works out to something like 50
spams per day.

2 or 3 weeks ago, we pulled the plug and moved to a static ADSL
connection, and have seen spam drop to about 5 per day.

The difference is that our MX record does not exist.  I'm going to keep
it that way unless I find that too much (or even any) legit e-mail is
not reaching us.  I'm basically looking for confirmation that this
strategy will work, as well as pointing out that the lack of an MX
record seems to be a powerful way to prevent spam.