Let us say I have a domain example.com that points to IP 192.0.2.4, hence in the DNS I would see:
example.com A 192.0.2.4
www.example.com CNAME example.com
Now, most MX records appear to be set in this way into the DNS
example.com MX 10 mail.example.com
mail.example.com A 192.0.2.4
Can I just do this?
example.com MX 10 example.com
By leaving out the: mail.example.com A 10 192.0.2.4
P.S. I looked into RFC "3.3.9. MX RDATA format" but it doesn't seem to say much
I have many sites (each one with its own domain) all on the same cPanel hosted server (let's say server IP is 1.1.1.1 and server main domain is myserver.com)
All these domains use third party DNS (not the cPanel hosted ones), I set up the DNS of each one of these domain to point to server IP. Example of how each domain DNS is currently set:
domainx.com -> A -> 1.1.1.1
domainx.com -> MX -> mail.domainx.com
mail.domainx.com -> A -> 1.1.1.1
www.domainx.com -> CNAME -> domainx.com
ftp.domainx.com -> CNAME -> domainx.com
This situation obliges me to repeat hundreds times the server IP 1.1.1.1 one time for each domain. In the event that server IP changes I will have to go through each domain DNS to update records with new IP.
So I thought why not use CNAME to avoid rewriting server IP everywhere?! I could set each domain DNS like the following:
domainx.com -> CNAME -> myserver.com
domainx.com -> MX -> mail.myserver.com
mail.domainx.com -> CNAME -> myserver.com
www.domainx.com -> CNAME -> myserver.com
ftp.domainx.com -> CNAME -> myserver.com
But I read that domainx.com -> CNAME -> myserver.com is evil, see this and this.
But what alternatives do I have to avoid rewriting server IP everywhere?
SCENARIO:
mydomain.com is the main website, we do send/receive mail using
[email protected]. mydomain.com DNS has got an SPF record "v=spf1 a mx ~all"
mydomain.net is just an alias for mydomain.com, but we do NOT send mail
using [email protected]. Therefor mydomain.net DNS has got an SPF record
"v=spf1 -all" to acknowledge everyone it does not send mail
Since mydomain.net is an alias for mydomain.com I wanted to use CNAME in DNS, thus:
mydomain.net -> CNAME -> mydomain.com
www.mydomain.net -> CNAME -> mydomain.com
But by doing this I noticed that when testing SPF for mydomain.net with a DNS tool like this the SPF returned is the one in mydomain.com "v=spf1 a mx ~all" and NOT as I would expect the "v=spf1 -all"
Is there a way to use different SPF for the two domains, by still using CNAME
I have somedomain.com on IP 1.1.1.1
I send/receive mail using Outlook connecting to mail.somedomain.com
So my DNS records for somedomain.com are the typical:
www.somedomain.com >>> A >>> 1.1.1.1
somedomain.com >>> A >>> 1.1.1.1
somedomain.com >>> MX >>> mail.somedomain.com
mail.somedomain.com >>> A >>> 1.1.1.1
But I also send some mails (using directly PHP mail function) from another server that is on anotherdomain.com and IP 2.2.2.2
I tried to setup SPF record using Microsoft wizard (the old days Open SPF wizard does NOT work anymore)
The SPF created by the wizard is this:
v=spf1 a mx ip4:1.1.1.1 mx:mail.somedomain.com ip4:2.2.2.2 -all
But I get some mails returning back when sent from 2.2.2.2 with the message: SPF Failed - not authorized message
Do you know what the right SPF value is for this scenario?
EDIT 1: as asked by Minsuk Song I post the SPF failed message
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
[email protected]
SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=120379:
host imp-3.mail.tiscali.it [213.205.33.247]: 550 5.1.0 <[email protected]> SPF Failed - not authorized
------ This is a copy of the message, including all the headers. ------
------ The body of the message is 116808 characters long; only the first
------ 106496 or so are included here.
Return-path: <[email protected]>
Received: from mild by server081.mildfred.com with local (Exim 4.77)
(envelope-from <[email protected]>)
id 1SRRp1-001a8D-8Z; Mon, 07 May 2012 13:34:07 -0400
To: <[email protected]>
Subject: ...
EDIT 2: as correctly noticed by nickgrim when I send mail from IP 2.2.2.2 I send them using an address that is on the somedomain.com (which is on IP 1.1.1.1). The reason I do this is that in case the mail gets rejected for any reason (as it happened) I get notified on an existing address <[email protected]>.
I have some domains registered that do not send mails.
I have totally removed MX record for these domains on my DNS.
Is it still useful to set an SPF record in order to avoid spammer to send mails as these domains?
I read here that for domains that do not send mail the SPF record setting is always:
mydomain.it. TXT "v=spf1 -all"
This is the simplest possible SPF record: it means your domain mydomain.it never sends mail.
But do I still need to set these since I even removed the MX record?
What I'm afraid is that some spammer uses one of these domains (domainA) and sends spam, since domainA is on the same IP of domainB that DO sends mail, I'm afraid an ISP could ban as spam mails coming from such IP and therefor mail coming also from domainB will be banned too.
Thanks!
FYI: I'm using a cPanel account with dedicated IP to host domains the mail server usese the same dedicated IP
UPDATE: from answers below I understood that for this specific case, SPF are not needed except for helping the interent in recognizing immediately as spam a spoofed email address using one of those domains. But no one answerd to the last part of my question.
in all my Apache servers I use hotlink protection because I hate the idea someone could stick my images/flash in their sites using my server bandwidth.
In order to make hotlink protection work, in my Apache .htaccess I simply use this:
#Hotlink protection (only for www.domain.it cause http://domain.it is being redirected)
RewriteCond %{HTTP_REFERER} !^http://www.domain.it/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.domain.it$ [NC]
RewriteRule .*\.(wav|swf|jpg|jpeg|gif|png|bmp|js)$ - [F,NC]
This works well, but I recently dicovered that when I ask for http://www.domain.com/somepage.htm/ (with final slash) the hotlink protection seems to be triggered and server stops page to download .(wav|swf|jpg|jpeg|gif|png|bmp|js) files
Do you know how could I fix this in .htaccess???
Before today I even thought that the server should return an error if I enter as URL http://www.domain.com/somepage.htm/ (with final slash). But I saw it's normal because if you look for http://www.php.net/docs.php it returns the same page of http://www.php.net/docs.php/ (final slash).
Why is that, could you explain me a bit?!
Thanks
Is anyone using servermojo to monitor its own website/server?
Is it a good (and quite cheap 30 buck / year) way to monitor a website/server uptime and reliability?
When I look at Awstats 404 errors I see sometimes strange referrers. For example on www.mydomain.com I might see a 404 error reported in Awstats that says:
URL (not found) Referrers
some-file.jpg http://www.mydomain.com/some-page.html
some-file.jpg is a file that does not exist, so it's not strange that if someone tried to reach it got back a 404 from server.
The strange part is that the referring page DOES NOT EXIST TOO, I mean http://www.domain.com/some-page.html DOES NOT EXIST, so how could it be the referrer?
Is it some client cheating the referrer?
Thanks!
Let's say:
I would like that when a person in the US visits www.example.com the website is shown by the server in US, but when a person in Europe visits, the website is shown by a server in the UK.
Is this possible using the same domain (with no sub domain redirections such as us.example.com and uk.example.com) by simply adding/modifying DNS records?
If (1) is YES, how do I set up the DNS records of www.example.com in order to accomplish this?
If (1) is NO, are there other solutions available to accomplish this, and what are these solutions?
I suppose that hosters who provides unlimited mail quota are only claiming it unlimited, and hope that they won't run out of disk space. Correct me if I'm wrong.
In order to do such trick they will have probably to calculate the average real quota used by the average user.
Let's say on a 100 GB space hosting I offer to 20 x 1GB POP3 emails, obviously if all user fill their mail my server would stop working cause they would require 200 GB, but I think I can expect this trick to work cause it will never happen (or it's extermly unprobable) that all user fills up all their mails, average user use Outlook and some will leave mail on server, others won't leave mail on server except when they are on vacation cause theyr PC is off and Outlook won't download mails.
But the QUESTTIONS are:
Thanks to any answers/suggetions you might provide.
Let's assume:
I have thousands of domains on same Apache server.
Each domain is in a folder under server public_html document folder, so it can be accessed by calling "www.somedomain.com" or by calling "www.serverdomain.com/somedomain_folder"
In each domain there is a website who needs a certain script.php (identical for each domain).
From a coding point view, its obvious that it's better to use a unique script.php, so when i update it with new features/bug fixes etc, I need to update on server only one file and it will work for all domains.
But from a server point of view? If i use a unique script all domains will access it at the same time, will the server run slower compared to the situation where each domain called its own script?
in order to measure aprroximately the rouitng distance (to see if a server is close to my country or too far away) I usually use ping command.
I'm in Italy,
Unfortunately some web hosters turn off the ping reply on their servers, so my question is how do I detect the routing distance, is there another easy to use command in Windows to accomplish the same task?
Thanks!
I own a typical shared IP hosting plan and domain. I can modify the DNS of the domain from the control panel. The mailserver shares the same IP address, so my typical DNS config is:
www.mydomain.com A -> myIP
mydomain.com A -> myIP
ftp.mydomain.com A -> myIP
mail.mydomain.com A -> myIP
mydomain.com MX(10) -> myIP
I read some Q&A on this site where they suggest to add PTR record mainly for mailserver.
I would like to add PTR record to my domain, I have got two questions:
1) can PTR record be added even if the hosting/mailserver are on a shared IP address? Or do I need a dedicated IP.
2) How do I setup PTR record, I mean does it look like A record:
mydomain.com (PTR) -> myIP
Does anyone have an idea of what's the impact on a website performances when activating Hotlink protection on server.
FYI: hotlink protection disallows other websites on other servers to place an image on their websites that directly refers to my websites. For instance let's say mywebsite.com is including an img file called test.jpg, anotherwebsite.com can NOT place in its pages this line:
<img src="http://mywebsite.com/test.jpg">
because mywebsite.com server would recognize that such request is not coming from mywebsite.com and stops the request, therefor anotherwebsite.com woudl display nothing in place of the image.
Actually my websites on which I activated Hotlink protection do not seem to run slower. But I'm just wondering waht's behind it, I suppose Apache web server needs to check for every request for an image and see where such request comes from, so in some way it should decrease performances.
I need to put on a website videos that can ba shown using a common swf player (like flowplayer).
Videos are about 3/4 minutes each (400 MB) in MPEG4/H264 compression.
I was thinking to buy a normal hosting plan package. But how much bandwidth/month do you think I need? Let' say I could have 5000 visitors per day watching each one of them an average of 1 video.
BTW: do you think it's normal that a 3/4 minutes video take 400MB in space?
Thanks!