On 05/12/15 06:28, sb wrote: > I received (yet another) SPAM/UCE from an address without MX record.
And you will also receive legitimate mail from servers without an MX, and sometimes even without an A record. MX (and the fallback to A) records have nothing to do with what addresses mail is supposed to come *from*. Legitimate senders may have multiple different submission servers for various reasons and this has absolutely nothing to do with which server(s) they receive mail on. Also the lookup key for MX records is the domain name of an email address, *not* the hostname of a submission server. It is not only not required that the hostname of a submission server have an MX record, it is actually unusual. Your thinking here is flawed. Don't do this, you will only end up rejecting lots of legitimate mail. Peter
