Re: sendmail?
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.
--
Grant