[twsocket] mx lookup

2008-05-08 Thread Wilfried Mestdagh
Hello,

To find out which is the smtp server I have to send mail to for a
particular domain I can use the MXPreference[n] property of DnsQuery
component. But in what case there can be multiple results ? (I tryed a
few and get only 1 result 'answer#1 in demo program').

What is the MXExchange[n] property for ?

--
Rgds, Wilfried
http://www.mestdagh.biz

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Re: [twsocket] mx lookup

2008-05-08 Thread DZ-Jay
Wilfried Mestdagh wrote:
 Hello,
 
 To find out which is the smtp server I have to send mail to for a
 particular domain I can use the MXPreference[n] property of DnsQuery
 component. But in what case there can be multiple results ? (I tryed a
 few and get only 1 result 'answer#1 in demo program').

RFC specifies that entries can have multiple MX records with a 
preference number.  The lower the value, the higher the preference. 
This is mostly used by large ISPs that have multiple hosts processing 
mail, for fault tolerance or load balancing.  For example, AOL and 
Earthlink have about 5 mail servers each, all with their own MX record.

dZ.

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Re: [twsocket] mx lookup

2008-05-08 Thread Wilfried Mestdagh
thanx Dz and Arno,

some more questions. What about the MXPreference? For example if I do a
mx lookup for sonal.be it returns mail.sonal.be with value 10 and
mxl.sonal.be with value 50. Does this mean one of the 2 is preferred?
and if so the one with the lowest value or the highest one?

---
Rgds, Wilfried [TeamICS]
http://www.overbyte.be/eng/overbyte/teamics.html
http://www.mestdagh.biz

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Re: [twsocket] mx lookup

2008-05-08 Thread Wilfried Mestdagh
Sorry forget this mail I did not read the answer from DZ good :(

---
Rgds, Wilfried [TeamICS]
http://www.overbyte.be/eng/overbyte/teamics.html
http://www.mestdagh.biz

Thursday, May 8, 2008, 16:42, Wilfried Mestdagh wrote:

 thanx Dz and Arno,

 some more questions. What about the MXPreference? For example if I do a
 mx lookup for sonal.be it returns mail.sonal.be with value 10 and
 mxl.sonal.be with value 50. Does this mean one of the 2 is preferred?
 and if so the one with the lowest value or the highest one?

 ---
 Rgds, Wilfried [TeamICS]
 http://www.overbyte.be/eng/overbyte/teamics.html
 http://www.mestdagh.biz


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Re: [twsocket] mx lookup

2008-05-08 Thread DZ-Jay
Wilfried Mestdagh wrote:
 thanx Dz and Arno,
 
 some more questions. What about the MXPreference? For example if I do a
 mx lookup for sonal.be it returns mail.sonal.be with value 10 and
 mxl.sonal.be with value 50. Does this mean one of the 2 is preferred?
 and if so the one with the lowest value or the highest one?

The one with the lowest numerical value is the preferred one.  In your 
case, mxl.sonal.be may be there for fault tolerance, in case the 
main server is down.  When they all have the same value, it's usually 
for load balancing, so you are free to pick the one with the lowest latency.

dZ.

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