If an ISP has "mail.ispxxx.com" for it's POP server, and "mail.isp.xxxx.com" for it's SMTP server, does that mean they only have ONE server for all mail, incoming and outgoing? That sounds a little dangerous to me; the cheap way out. -- Rev. 1:7 ; Registered Linux User #153217
This may or may not be true. They could have a group of clustered servers which all respond to the same DNS. Maybe a loadbalancer in front of them which responds and then redirects the traffic to one of the boxes behind it, or several other potential configurations in which they hav more than one machine which responds to the same address. Or, you may be right, they may be cheap and only have one box for each DNS. If it is a reputable ISP they will have more than one box. At least two each for smaller ISPs and many more for larger ISPs. Jim 03/24/02 09:14:05 PM, Jerry Van Brimmer <jerryvb@vei.net> wrote:
If an ISP has "mail.ispxxx.com" for it's POP server, and "mail.isp.xxxx.com" for it's SMTP server, does that mean they only have ONE server for all mail, incoming and outgoing? That sounds a little dangerous to me; the cheap way out.
-- Rev. 1:7 ; Registered Linux User #153217
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On Sunday 24 March 2002 10:14 pm, you wrote:
If an ISP has "mail.ispxxx.com" for it's POP server, and "mail.isp.xxxx.com" for it's SMTP server, does that mean they only have ONE server for all mail, incoming and outgoing? That sounds a little dangerous to me; the cheap way out.
Use the 'dig' command on each to verify if the host resolves to the same ip address. It's kind of doubtful that an ISP would only run one mail server. More than likely the ip / host for the smtp server is a mail gateway, there could be multiple servers behind the gateway box. -- George Auch SuSE Pro 7.3 Linux ns1 2.4.18 #1 Sat Mar 2 08:38:16 EST 2002 i686 unknown
Here's what I get when I 'dig' mail.vei.net, my mail server: jerry@linux:~> dig mail.vei.net ; <<>> DiG 8.3 <<>> mail.vei.net ;; res options: init recurs defnam dnsrch ;; got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3 ;; QUERY SECTION: ;; mail.vei.net, type = A, class = IN ;; ANSWER SECTION: mail.vei.net. 7m32s IN A 207.244.8.40 ;; AUTHORITY SECTION: vei.net. 13h6m53s IN NS NS3.vei.net. vei.net. 13h6m53s IN NS NS4.vei.net. vei.net. 13h6m53s IN NS NS2.vei.net. ;; ADDITIONAL SECTION: NS3.vei.net. 13h6m53s IN A 207.244.8.3 NS4.vei.net. 13h6m53s IN A 207.244.18.240 NS2.vei.net. 13h6m53s IN A 207.244.8.2 ;; Total query time: 205 msec ;; FROM: linux to SERVER: default -- 198.6.1.150 ;; WHEN: Sun Mar 24 19:41:45 2002 ;; MSG SIZE sent: 30 rcvd: 148 jerry@linux:~> What does it all mean? On Sun, 24 Mar 2002 22:16:21 -0500 George Auch <gwauch@auchnet.net> wrote:
On Sunday 24 March 2002 10:14 pm, you wrote:
If an ISP has "mail.ispxxx.com" for it's POP server, and "mail.isp.xxxx.com" for it's SMTP server, does that mean they only have ONE server for all mail, incoming and outgoing? That sounds a little dangerous to me; the cheap way out.
Use the 'dig' command on each to verify if the host resolves to the same ip address.
It's kind of doubtful that an ISP would only run one mail server.
More than likely the ip / host for the smtp server is a mail gateway, there could be multiple servers behind the gateway box.
-- George Auch SuSE Pro 7.3 Linux ns1 2.4.18 #1 Sat Mar 2 08:38:16 EST 2002 i686 unknown
-- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/support/faq and the archives at http://lists.suse.com
-- Rev. 1:7 ; Registered Linux User #153217
Here is the relevant info: # dig vei.net mx ; <<>> DiG 8.3 <<>> vei.net mx ;; res options: init recurs defnam dnsrch ;; got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 4 ;; QUERY SECTION: ;; vei.net, type = MX, class = IN ;; ANSWER SECTION: vei.net. 2h13m22s IN MX 10 mail.vei.net. [snip] So they have only one mail server unless they play funny games with load balancers. If the POP server is at the same IP address, they may or may not be on the same host. E.g., firewall port redirection or NAT. On the right hardware and software, you can push 1 million messages per day thru a Intel box. Performance may or may not be a bottleneck. Redundancy might be nice, but buy good hardware and keep some spares around. HTH, Jeffrey Quoting Jerry Van Brimmer <jerryvb@vei.net>:
Here's what I get when I 'dig' mail.vei.net, my mail server:
jerry@linux:~> dig mail.vei.net
; <<>> DiG 8.3 <<>> mail.vei.net ;; res options: init recurs defnam dnsrch ;; got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3 ;; QUERY SECTION: ;; mail.vei.net, type = A, class = IN
;; ANSWER SECTION: mail.vei.net. 7m32s IN A 207.244.8.40
;; AUTHORITY SECTION: vei.net. 13h6m53s IN NS NS3.vei.net. vei.net. 13h6m53s IN NS NS4.vei.net. vei.net. 13h6m53s IN NS NS2.vei.net.
;; ADDITIONAL SECTION: NS3.vei.net. 13h6m53s IN A 207.244.8.3 NS4.vei.net. 13h6m53s IN A 207.244.18.240 NS2.vei.net. 13h6m53s IN A 207.244.8.2
;; Total query time: 205 msec ;; FROM: linux to SERVER: default -- 198.6.1.150 ;; WHEN: Sun Mar 24 19:41:45 2002 ;; MSG SIZE sent: 30 rcvd: 148
jerry@linux:~>
What does it all mean?
On Sun, 24 Mar 2002 22:16:21 -0500 George Auch <gwauch@auchnet.net> wrote:
On Sunday 24 March 2002 10:14 pm, you wrote:
If an ISP has "mail.ispxxx.com" for it's POP server, and "mail.isp.xxxx.com" for it's SMTP server, does that mean they only have ONE server for all mail, incoming and outgoing? That sounds a little dangerous to me; the cheap way out.
Use the 'dig' command on each to verify if the host resolves to the same ip address.
It's kind of doubtful that an ISP would only run one mail server.
More than likely the ip / host for the smtp server is a mail gateway, there could be multiple servers behind the gateway box.
participants (4)
-
George Auch -
James Bliss -
Jeffrey Taylor -
Jerry Van Brimmer