> Date: Friday, October 16, 2020 08:02:30 +0000
> From: Jason Long <hack3r...@yahoo.com>
>> On Friday, October 16, 2020, 01:13:45 AM GMT+3:30, Richard
>> wrote:
>>
>>
>>> Date: Thursday, October 15, 2020 18:57:29 +0000
>>> From: Jason Long <hack3r...@yahoo.com>
>>>
>>> If the DNS administrator give me an A record then can I sending
>>> and receiving emails from the Internet by the current
>>> configuration?
>>
>> Assuming no MX, if an A-record is set up to point to a machine
>> (properly configured, including with postfix or some other MTA)
>> reachable on port 25 at the IPnumber, then it should be able to
>> receive mail inbound.
>>
>> To be able to send mail directly to target mail servers you'll need
>> to be able to connect outbound on port 25. To successfully deliver
>> it, including to correspondents' inboxes, you'll need a matching
>> Rdns record as well as the following:
>>
>> (this list is taken from an earlier message from Ahsan Khan
>> responding to one of your questions):
>>
>> 1. SPF
>> 2. DKIM records
>> 3. DMARC records
>> 4. IP Warmup
>> 5. Check the scores at mail-tester.com.
>> 6. Domain reputation
>>
>> There are a range of nitty things underlying all this which you
>> will need to read up on so that you understand how mail, DNS,
>> etc. work.
>>
>> You may be better off sending your mail outbound by way of a
>> smarthost at your provider.
>
> Thank you.
> Thus, in Postfix or Dovecot configuration file I can't change the
> standard record?
>
Asked and already answered, multiple times, by various people.
It's also not clear how that question follows on from the q/a that it
is in reply to.
To run a mail server successfully takes a base-level knowledge of the
underlying protocols (and interoperability), not something gotten
from scattershot questions. Try looking at some of the references
previously mentioned.
