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

[base60]

sm5w2 at hotmail.com wrote:
> 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.

And what you're being told is that the presence or absence of an MX
record has no bearing on the amount of spam you receive.

If legit email can be delivered when you have no MX, so can the spam.

> 
> 
>>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.

Yeah, they check for an MX first and then an A.

If you don't have an MX, obviously you won't find one cached.

> 
> 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.

You're not listening: it **DOESN'T MATTER** if you have an A record
for the domain.

> 
> 
>>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.

Believe what you want.

> 
> 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.

Whatever.

> 
> 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.

Believe what you want.