G Suite (Google Apps) Dual Delivery – Use cases-:

  • You have decided to switch to Google Apps from your legacy mail server and ready to switch your MX records to Google mail servers, however you would prefer to do that in phases, may be to get enough time for change management and system validations, which make you consider dual delivery Google Apps
  • You have your own business requirements where you want all emails which come to your Google Apps mail server, should be sent to your legacy mail server as well, this dual delivery flow of emails is called “Email Dual Delivery”

 

Dual Delivery Google Apps – Solution Overview-:

  1. All the emails of your domain (lets call it gappsfix.com) will first come to Google Apps mail servers
  2. These emails will then delivered to your users who have their account on Google Apps
  3. You will define another desitanation in Google Apps where Google will forward all emails which comes to it for your domain

 

Configuraiton of Incoming email flow in dual delivery through Google Apps-:

  • Objective of this email flow is to configure the system in such a way, that all the emails sent to your domain should land at Google Apps mail servers first, and then a copy of all these emails will be sent to your legacy (lets call is MS Exchange 2007) too.
  • Below are the step by step instructions (with screenshots) to configure inbound email flow of dual delivery through Google Apps

Step 1 -> Setup your primary domain to work with Google Apps

Perform following steps for it, you may click on following links to see respective step by step tutorial with screenshots

 

Step 2 -: Collect your legacy mail server IP (or host name)

  • You will need IP address of the server which hosts your mail server
  • If you have load balancing in place through multiple MX records for your exchange server, its better to collect the host name of your exchange server
 

Step -3: Login to Google Apps Control Panel

  • Login to your Google Apps Control Panel (Instructions HERE)

Explanation of this step-:

  • To make any administration level changes in Google Apps to achieve dual delivery in Google Apps, we will first need to login to Google Apps Administration Console
 

Step 4 -> Navigate and click on “Google Apps

  • Once you are in your Google Apps control panel, click on “Google Apps” as shown in the screenshot below

Explanation to this step-:

  • Now we have landed on Google Apps Admin Dashboard where we can administrate all Google Apps services, however for our specific requirement, we will click on “Google Apps”

Step 5 -> Navigate and click on click on GMAIL

  • You will all the services offered under Google Apps here, click on GMAIL, as shown in the screenshot below

Explanation to this step-:

  • We can see lot of Google Apps services here, however our requirement is to configure dual delivery of emails, and for that we will click on “Gmail”

Step 6 -: Navigate and Click on “Hosts”

  • Once you are in the gmail settings, click on the “Hosts” link as shown in the screenshot below

Explanation of this step-:

  • Hosts-: We can define hosts in google apps with putting the IP address or host name, these hosts can later can be used for routing emails.
 
  • Step 7 -> Navigate to Adding Route

    • Under Hosts, click on “Add Route” as shown in the screenshot below

    Explanation of this step-:

    • Hosts tab provides flexibility of creating routes, each route can contain one (or multiple) IP address or host name

Step -8 -> Create Route with your host or IP

  1. Write a meaning ful description for your route
  2. Select “Single” OR “Multiple” host/s as required
  3. Put the IP address of the your legacy/exchange server
  4. Provide the port number where your mail server accepts emails (Allowed ports are 25, 587, 1024-65535)
  5. Save Changes

Notes-:

  • If you have more than one IP or need load balancing, you can choose “multiple hosts”
  • If you are putting IP, DO NOT select “Perform MX look up on host”
  • If you are putting host instead of IP address, make sure your host is correctly pointing to your mail server IP address

Step 9 -> Configure a “Receiving Routing” rule in Google Apps Control Panel

  1. Click on “General Settings”
  2. Scroll down to find “Receiving Routing”
  3. Click on the “Configure” button in front of “Receiving Routing”

Explanation of this step-:

  • We need to define dual routing of emails, which can be done by creating a rule under “Receiving Routing” in Google Apps, in this step we are just navigating towards creating this rule.

Step 10 -> Add a description to your “Receiving Routing” rule, along with defining whether this is applicable on internal and/or extenal emails

  1. Add a meaningful description to your receiving routing rule, so your colleague can understand it too in your absence
  2. Select “Inbound”

Note-:

  • Here “Internal – receiving” means which are being sent from one Google Apps user to another google apps user in your domain, as we are configuring dual delivery and delivering all emails which are coming to Google Apps, to microsoft exchange, there is no need to select “internal receiving” here.

Explanation of this step-:

  • In this step, we are defining that on which emails, our rule will be applicable, so we have kind of defined the IF statement here, stating “all incoming emails”

Step 11 -> Setup “Also deliver to” condtion

  • In this substep, we are telling Google Apps, to deliver all emails to an another destination as well, we will do it by clicking on “Add more receipients” checkbox

Explanation of this step-:

  • We are defining “THEN” statement here, stating to add additional recipients to all incoming emails

Step 12 -> Do the advance settings for changing the route to your legacy server

  1. Click on “Add” button as shown in the screenshot below, to add another mail desitnation
  2. Select “Advanced” from dropdown as shown in the screenshot below
  3. Click on “Change Route” and select the route which you defined in Step (Microsoft Exchange Route in our example)
  4. Either you can select “Do not deliver spam to this recipient” or instead of it, you can checkmar “Add X-Gm-Spam header” to let your legacy server know the spam status

Explanation of this step-:

  • Look at the explanation of Step to better understand it.
 
  • Step 13 -> Avoid delivering spam to your legacy server

    • Save your changes

    Explanation of this step-:

    • Look at the explanation of Step to better understand it.

    Note -: If you want your legacy server to handle spam, you may uncheck “do not deliver spam to this recipient” and check “Add X-GM-Spam header” to let your legacy server identify it

Step 14 -> Apply the conditions we configured by clickin on “Add Setting”

  • Click on “Add Setting” to save the rule

Explanation of this step OR what we have done so far-:

  • We have created a “Recipient Routing” rule which asks Google to add additional recipient (legacy server) to all incoming emails, resulting all emails will come to your Google Apps domain first, will be delivered to users Gmail box (whichever users you have in Gmail), and then all these emails will be sent to your legacy mail server too through this rule.

Congratulations

  • Congratulations, you have now configured Google apps dual delivery, in case if it doesn’t work for you, or you have ideas to make this article better/simple, don’t hesitate to put that in comments below
  • In case if you have any query regarding Google Apps dual Delivery or any other issue regarding Google Apps, feel free to write