Quote:
Originally Posted by cuskitco
Ultimately I want emails sent to anyemailaddress@ourdomain.co.uk to arrive at our Exchange Server, here in our offices
But, if I set mail.ourdomain.co.uk to point to eUKHosts Mail Server, then won't it try and deliver the email to the anyemailaddress@ourdomain.co.uk located at eUKHosts' Smart Email system, rather than our Exchange Server here?
How will your Smart Email system know to deliver the emails to our Exchange Server here?
This is where I expected the Mail Forwarding to come in by forwarding mail from the ourdomain.co.uk domain located on your system, to ourdomain.co.uk located on our system (SBS 2008 with Exchange Server)
My concern is that if Mail Forwarding is indeed used here, then we will have to create Mail Forwarders for each emailaccount@ourdomain.co.uk! If this is true then it is bad news, and not a preferred solution - I hope I have missunderstood 
So, in summary, if I set mail.ourdomain.co.uk to point to eUKHosts Mail Server, how will your mail server know how to deliver our emails to our Exchange Server, here in our offices? |
Hi Adam,
Here are the answers to your questions & some additional information as well on setting up SmartHost in mail servers for email forwarding. There's no need to do it for each & every email address on your domain(s), but either for a particular domain or an entire server. Hope you find it useful
Backup MX differ from Smart Hosting & are for when you are running a mail server and you want to ensure you don't lose mail during unexpected downtime. This doesnt involve into forwarding the emails when either of the server goes up & down, but is merely for email redundancy.
An MX record's preference value determines its order of priority, with
0 being highest/first priority and
50 being lowest/last priority. If the highest priority mail server is unavailable for any reason (time out, power outage, etc.), sending mail servers try to connect to the next-highest mail server; if this mail server is also unavailable, it goes to the next-highest, & so on down the list.
Here is an example of a domain having two MX records:
domain.com 41200 MX 10 mail.domain.com
domain.com 41200 MX 20 exchg.domain.com
mail.domain.com has a preference of
10 & exchg.domain.com has a preference of
20, so sending mail servers would try to connect to mail.domain.com first, and exchg.domain.com second. You can have as many MX records as you want, & define the order of importance using their preference values for any remote/backup servers you need..
Now that was about having Backup MX records for your domain, here's about the SmartHost technology:
SmartHost using a MailEnable server:
Smart hosted domains are domains that are redirected to remote mail hosts. MailEnable or the mail server hosted with Eukhost can function as a smart host. This means that it can collect mail for another host [Exchange or any other], & pass the email on..
Our mail server can smart host mail for one specific domain or for all outbound SMTP mail.. The preferred means of smart hosting is on a per domain basis. The reason for this is that it is less likely to create infinite message loops, where messages are forwarded infinitely from one mail host to another.
MailEnable will always check for local delivery [Eukhost] above sending the message to any remotely configured DNS server [Exchange]. To override this behaviour requires a system utility called MERoute. To force MailEnable to deliver to an external address over local delivery, it'd require this MERoute utility. It'll force any mail being delivered to a post office to be smart hosted out regardless of a mailbox being configured on the server which is useful for local traffic.
You can also use both the servers at a same time, ie: keeping the Eukhost server as a backup mail server, in case the Exchange server goes down. This can be done by configuring an additional MX record to have a backup MX, ie. with a different priority. This will mean that if the primary mail server is offline, that the secondary backup MX will accept the e-mail on behalf of the primary..
A target server, ie. one that knows how to deliver to the relevant user's e-mail mailbox is typically one which is the most preferred. Lower priority servers, a.k.a. backup MX or secondary MX, usually keep the messages in a queue waiting for the primary server to become available.. If both servers are online or in some way connected to one another, the backup MX will typically queue a message briefly & immediately forward it to the primary MX. The backup MX acts as a store-and-forward mail server.
To do this, configure the secondary MX mail server with all the domains to host with Eukhost, & use the smart host option for each domain, or in the SMTP service properties so that it is directed to the primary MX mail server... This way, if the primary goes offline, then the secondary will accept the mail, & queue it until the primary server is back online.
In order to configure a back-up server, create the same domains on the backup server, but no email addresses. Then, set the smart host for each domain to point to the primary server. This means that if the primary server goes down, the email will be delivered to the secondary server. This server will accept all email addressed to a domain, & then try to send this email to the primary server. Since the primary server may still be down, the emails will sit in the outbound queue, & be retried (the retry interval can be set). When the primary server comes back online, then the banked up email is sent through. This will resolve the back-up of email being received..
SmartHost using a SmarterMail server:
SmartHosting allows one SmarterMail server to accept mail for another remote server.. This can be used in a backup scenario so that if the primary mail server goes down, the secondary server will accept mail for it until the server goes back online.. For more information about the roles of SmartHosting, please see Gateways & Other Server Roles.
To configure SmartHosting correctly, changes need to be made on the secondary server & to DNS records of domains that will have SmartHosting supported.
1. Add SmartHosts - In the secondary server, add all IP addresses of the primary server to the SmartHost list.. Mail that resolves to MX records that do not match these IP addresses or accounts on the secondary server will be rejected.
2. Setup MX records - In DNS zone of your domain, add an MX record for the secondary mail server that has a LARGER preference value than the primary mail server. Note: In MX records, lower preference value servers are tried first.
3. Set appropriate retry times - Since the intent of SmartHosting is for the secondary server to be a backup server, adjust the retry times in General Settings to values that are more conservative. Good defaults would be: 10 minutes, 10 minutes, 10 minutes, 1440 minutes.
SmarterMail was designed to support one server in several of the below mentioned roles. eg: one server could act as an Incoming Gateway, an Outgoing Gateway, & a Backup MX. SmarterMail can also take on one of these roles when placed together with a competing mail server [MailEnable, Exchange, etc].. ie: using SmarterMail as an outgoing gateway on a server other than your primary mail server may help to resolve problems with stability of other mail servers...
Primary mail server:
* Use for storing email for defined users.
* Accessible through POP, SMTP, IMAP, & over the web.
Backup MX Server:
* Use as a backup for mail delivery in case of short amounts of downtime or delivery problems on your primary mail server..
Incoming Gateway server:
* Use to host third party anti-virus and/or anti-spam software products in order to reduce load on primary server.
* Reduces load on primary server by managing all incoming sessions & performing abuse/intrusion detection.
Outgoing Gateway server:
* Use as a delivery mechanism to reduce load on your primary servers.
* Also use as a method to combat blacklisting. If the server gets blacklisted, rotate the primary IP on the network card to a different one to send out on the new IP.
Please let know how you'd like us to proceed taking the above scenarios into consideration...
Emailing & DNS
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