Email Sending Issue... How to send emails quickly

[mirfan]

We are using Exim on CPANEL server with CENTOS 5.
Problem is that our users are in two different data centers in US and China. And china datacenter users having difficulties for sending emails along with attachments most of the time because of slow connectivity between US and China datacenters.Because china users have to connect to US DC SMTP server and becz of slow connectivity issues users suffers alot.

At this point, i am trying to achieve functionality like china users will connect to china DC for sending
emails i am looking to configure secondry SMTP server on china DC. and china SMTP server will than send
relay emails to main SMTP server in US DC which will responsible to send emails finally.

Please let me know this will improve email sending from China ? How to accompish this ? or is there any better solution to resolve this issue ?

currently main mail server which hosts all users mailboxes. and i don't want to seperate domain name between two datacenters. I still think separate SMTP server on both datacenters can solve email sending issues but how to accomplish this without changing any user email domain e.g. [email protected] or anyohter idea ?

 

[cPanelTristan]

Is there a reason a new thread was opened when this was previously asked about in this thread:

http://forums.cpanel.net/f43/slow-link-241121.html

Couldn't this have been placed into the prior thread with any new questions?

As for your current setup, what do you have specifically setup for the US and the Chinese machines? Are they using primary and secondary MX as was suggested in your original thread? If they are, you want to instead have both serve as primary but allow relaying from the Chinese server through the US one?

 

[mirfan]

Sorry for opening of new thread.

Currently we have only primary mail server hosted on US DC with address mail.example.com and all emails from outside world routes directly to that machine. When china user send/recieve email to @example.com it has to connect directly and this performs bad.
Yeah, i am looking to configure some sort of relay on china DC mail1.example.com that whenever client sent an email to @example.com it will first connects to mail1.example.com and this will relay email to US DC. I thought this will improve overall send/recieve from china because connectivity between CHina & US DC is much improve.

I didn't implemented the primary / secondry MX. I stuck to configure email accounts on both machines, as i am not sure which API-based script to handle email account creation.

Also i thought relay emails from china to US DC is much better option.
Does Exim can be used to relay emails and how ?
or first suggestion with Primary / Secondry MX is much appropriate.

Thanks in advance for helping in this regard.

 

[cPanelTristan]

If you simply want to allow the server in China to relay through the one in the U.S., you can do the following steps noted:

http://forums.cpanel.net/f43/disabl...il-remotely-using-smtp-209401.html#post860592

 

[mirfan]

Thank you for reply.
So when relaying emails from china DC to US DC do i need to maintain mailboxes on both sides for authentication for china users ? or china users emails directly authenticated from US DC mail server ?
and finally do i need to create /etc/alwaysrelay file on china DC from where i am relaying to originated mail server on US ?

 

[cPanelTristan]

If you are going to relay through the U.S. machine from the Chinese machine, then as I state in that post:

If you are trying to allow that IP to relay, you need to do the following on the live machine (the one you are relaying through for the test script):

The file needs to be placed onto the U.S. machine as you are relaying through that machine.

You shouldn't need mailboxes on the U.S. machine if you are simply going to relay through it. I don't see how that will speed up email delivery, though, since you then have to go through a second machine rather than using 1 machine for sending.

Now, it seems like the only reason that this would be considered would be to try to mask the IP of the sending machine to get the U.S. machine IP instead so that the emails aren't flagged as spam or placed into junk due to having a non-U.S. IP. That's the only scenario where I can see this even being a worthwhile option to pursue.

 

[mirfan]

Sorry, i thought i didn't clear it properly.
We have main mail server on US DC where all users email boxes also resides. I have DC in china as well.
Now i want whenever china user send / recieve an email it should first go to china DC and china DC should be responisble to communicate to US DC main mail server exim. This is needed becz when end user from china directly connects from china to US mail server becz of bandwidth issue china user has to suffer.
I need some sort of mechanism on china DC which will send/fetch emails from US mail server. Just like a bridge in between because connectivity b/w DC is much better. As i foresee this is much better option while end user from china directly connects to US Mail server.

Please find the attach file a visual diagram to ellobroate it further.

Thanks for your help anyway.

 

[mirfan]

Tristan, can you please reply and let me know your opinion on this.
How to improve send/recieve emails for china users.

 

[cPanelTristan]

You can try to relay as I've already suggested when you mentioned relaying through the machine.

Of note, I was off and so there are other users who may be able to respond when I am unavailable. You may not always receive a response from the same individual on the forum.

 

[mirfan]

Hello,

Relaying from US to China DC will not help i think.
Actually when users from china tries to send email along with attachements it takes quite some minutes infacts sometime quite long because end user need to connect from china to US DC primary MTA and because of connectivity and bandwidth issue users face problems. However, as i said earlier, we also have machine in China DC and connectivity b/w china & US DC is much better.
I want solution something like when user sends email from china by using our domain @example.com it should connect China DC (we will install exim on china DC machine if require) which will rsponsible to send email to US DC. Also we don't want to switch china user mailboxes to China we need to keep all user mailboxes to primary MTA.
Through this we will foresee email sending will speedup atleast.
Please let me how to accomplish this or any other solution ?

 

[cPanelTristan]

You could create a smarthost to route all emails to that Chinese server for the sending server instead of the existing one. Here are details on creating a smarthost router:

https://forums.cpanel.net/f43/relay-all-mail-through-spam-filtering-appliance-155390.html#post766872

If that still isn't what you would like, I would highly suggest posting on exim mailing list with specifics on exactly what you require for them to determine how to go about doing it. They are the experts there.