how really function mx record?

[hmp_khauff]

ok suppose that i have a dns configured in windows server 2003 pc with ip x.x.x.2 and i have other pc with ip x.x.x.3 which one is the mail server. ok

i create host A record in dns with value: mail.mydomain.com pointing to x.x.x.3 then i configure in mail server the mail server name: mail.mydomain.com, domain name = mydomian.com ok.

finished with it, then y test with two account each one configured in differente computers. then i can send and receive mail perfectly.

so my question begin here: in this scenario why i have to create mx record? if only with A record it functions well. :S

 

[scsi]

Mx is only needed for recieving mail. It is not needed for sending it out. It tells the sending server where to send your mail for the domain.

 

[hmp_khauff]

Mx is only needed for recieving mail. It is not needed for sending it out. It tells the sending server where to send your mail for the domain.

if i only have A record (Host Record) when i send a mail how can other people receive the mail. remeber if i don't have mx record. and i could it.

i received and sent messages without mx record, only with the host record A

 

[scsi]

When you send an email your server you are sending from looks up the mx record of the other domain to see where to send it. I dont know how you can receive any email without a mx record the sending server would never know where the mail is supposed to be routed to.

 

[hmp_khauff]

When you send an email your server you are sending from looks up the mx record of the other domain to see where to send it. I dont know how you can receive any email without a mx record the sending server would never know where the mail is supposed to be routed to.

is it possible because it is internal? ok.... i am practicing with vwmare virtualization, i have the following scenario:

1 pc with windows server 2003 configured as dns and active directory
1 pc with daemon mail server as mail server
1 pc for test configured account in outlook express.

all the three pc has configured in dns the ip address of dns server (windows server 2003). and the network scenario is nat vmnet08 (customized))

so in 1 pc i configured an account in outlook express as.

smtp server: mail.mydomain.com
pop server: mail.mydomain.com
domain: mydomain.com
user: [email protected]
password: xxxxxxx

in other pc i configured an account in outlook express as

smtp server: mail.mydomain.com
pop server: mail.mydomain.com
domain: mydomain.com
user: [email protected]
password: xxxxxxx

so when i send a mail from peter's account to john's account, john's account inbox has received the mail from peter

when i send a mail from john's account to peter's account, peter's account inbox has received the mail from john's account.

so all this scenario function without mx record in the pc configured dns in windows server 2003, the only record that i have created is A record with value: mail.mydomain.com pointing the mail server daemon pc.

 

[floyd]

It works probably because peter and john are both users on the server sending the mail. Its not sending to a domain. Its sending to the user account.

 

[nobaloney]

By default, the dnslookup router in DirectAdmin will check for A records if no MX records are found. Why? Because even this many years after MX records were implemented, many misbehaving systems don't have MX records even though they accept email.

You can add a line to exim.conf to disable the A record lookup on a global basis; look here for more information.

Jeff