On 2008-12-27, Sahil Tandon <sahil@xxxxxxxxxx> wrote:
jkinz@xxxxxxxx wrote:
[...] you do not need an MX record to send or receive mail.
True, but many email systems will no longer accept email that
comes from a system/address with no valid MX record. Yet another
spam defense technique. As a result, if you don't have an MX
record much of your mail may be rejected, so these days having an
MX record is "almost" a requirement.
This is also false.
I used to have mail rejected because the sending domain didn't
have an MX record. After I set up my MX record, those systems
that used to reject mail started to accept mail.
Sending email from a domain without an MX record is perfectly
acceptable.
That depends. Some mail servers accept it, soem don't.
And, when you receive email from most major mailers (i.e.
gmail), the connecting system is not a valid MX.
I'm not sure what you mean by the phrase "the connecting system
is not a valid MX". The requirement in question is that the
sending domain has an MX record -- I don't think it has
anything to do with the connecting client machine.
If a real SMTP client attempts to send email to domainX, it
will first look up the MX and try sending there; if there is
no MX record, then the mail is directed at the A record. This
is all governed by RFCs. Can you give an example of a
legitimate SMTP server out there that rejects email based
solely on the fact that it comes from a domain with no MX
record?
It used to happen to me regularly, but I don't run my own mail
server any more.
I am sure some people do this, but I'd be surprised if it were
as prevalent as you suggest.
Back when I ran a mail server, I would have guessed that 5-10%
of servers required that the sending domain have an MX record.