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Old 06-29-2006, 02:26 PM   #1
shipon_97
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Cool What contains an MX


Dear Friend ,

1) I have Littlebit Confused about "MX" .

Suppose I have Two Office . Ist Office contains MAIN "Dns" And "A Postfix " Mail Server . Here my first office has the domain
"server.example.com"

Again My 2nd Office Also Have a real Domain let "red.aim.com" And also a Postfix Mail server . I want this real domain works via my Main "nameserver (First Office)" And also "red.aim.com" domain user get mail via my "1st office" DNS server . Now my question is ,In this situation , My 2nd Office Server is called MX ?

2)What is the difference between "relay-domians" and "access(/etc/mail/access)" file .
What is the function of these two files ?

Plz help.........
 
Old 06-29-2006, 02:41 PM   #2
MensaWater
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An MX record is a DNS record of what your mail server is. Mail itself has no MX record. For MX in your DNS zone file you just set the record. You have to have an address record in DNS as well.

Example from a fake zone file called dummydomain.com:

<white space> IN MX 10 smtp.dummydomain.com.
smtp IN A 192.168.3.3

The MX record says to use smtp.dummydomain.com as the mail server. The Address (A) record defines smtp(.dummydomain.com) as having IP 192.168.3.3.

The "10" next to MX is a priority designator. You can have multiple MX records and it will use the number next to MX in ascending order to determine which one to use. (Use 10 before 20, 20 before 30 etc...) The numbers don't have to be 10, 20, 30 etc... but most people do that to allow for inserting higher priority between existing MX records if necessary later.

Last edited by MensaWater; 06-29-2006 at 02:43 PM.
 
Old 06-30-2006, 11:21 PM   #3
shipon_97
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Smile what MX contains ?

Dear jlightner ,

Thx for ur help . I have the Following queries , plz help :

1) Suppose i make Two Mail server for my Domain :

mail1.example.com
mail2.exzmple.com //backup
For these mails i need to make entry into my DNS "Forward Zone" Like the following way :
IN MX 10 mail1.example.com.
IN MX 20 mail2.example.com.

Here the "Outcomings mail" first serch the "first mailbox(mail1.exzmple.com)" and then searc the "2nd one (mail2.exzmple.com)" . Now my question is :

If i want to make a situation , where the outcomings mail comes
to these both mail server at a time . i.e., When a mail comes from the outside then it goes to "mail1.example.com" & "mail2.exzmple.com" at a time so that my mail has less chance to loss .I want to make it for my mail security .Is it possible to do ?

2) My 2nd question is , when i need to MX entry then i write it into my "DNS Forward" Zone

IN MX 10 mail1.example.com.
IN MX 20 mail2.example.com.

Why i don't need to write these entry into "DNS reverse zone " ?
 
Old 07-01-2006, 08:47 AM   #4
MensaWater
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1) It won't go to both at the same time. It will try the higher priority (the one with 10) first and if that fails it will go the the lower priority one (the one with 20).

2) The MX record is a specialized record. You don't give it an IP address as you do Address (A) records. Reverse records are IPs to host (whereass forwards are host to IP) Therefore the reverse you would make would be for the A record which does have an IP address. If you'll notice in my example I indicated both an MX and an A record need to be created. The reverse of the A record will serve as the reverse of the MX (conceptually).
 
Old 07-02-2006, 11:50 PM   #5
shipon_97
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Question what mx contains ?

Dear jlightner ,

i want to make a situation , where the outcomings mail comes
to these both mail server at a time . i.e., When a mail comes from the outside then it goes to "mail1.example.com" & "mail2.exzmple.com" at a time so that my mail has less chance to loss .I want to make it for my mail security in the following way :

IN MX 10 mail1.example.com. //1st mailbox
IN MX 10 mail2.example.com. // 2nd mailbox
If i marking these two mail box in the above way (same priority marks) , then is it possible to come "outcoming" mail in these mail boxes at a time ?

Waiting for ur reply ... ...
 
Old 07-03-2006, 02:05 PM   #6
MensaWater
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The idea of the priority is so that you don't lose any mail. If the first mail server is down it will go to the second one. Its not clear to me why you would want it going to both at the same time - you'd end up getting two copies of the same email to the end user's mailbox.

In any event I don't know of any way to do that in BIND. There is a BIND mail list where people smarter than me may know. You may wish to check that out.
 
  


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