Knowledgebase: NotifyLink On Demand
SMTP Change for On Demand customers
Posted by Heather Burkett on 03 May 2010 03:11 PM

NotifyLink On Demand Customers:


 Currently, your NotifyLink On Demand Service is setup as follows:

 1. Users send a message from their handheld device.

 2. The device makes a connection to the NotifyLink On Demand Service

 3. The NotifyLink On Demand Service processes this message, and forwards the message to our SMTP Server (

 4. Our SMTP Server ( does an MX lookup, and then makes a connection to your server (over port 25) and sends the message as a “normal email”.

 a. This communication is currently allowed through your firewall, otherwise you would not be receiving email from your users when they send messages from their handheld devices


 In order to eliminate the extra step of sending the SMTP messages through another server, and to process these messages more efficiently, we are going to have your individual NotifyLink On Demand Service process the SMTP messages, and send them directly.  Customers will fall into one of two different scenarios, and they are described below:



 Customers who have firewall policies that ONLY allow specific external email:

 If you currently only allow specific companies to send you email, you may need to make an exception in your firewall.  Currently, you will most likely have an exception that allows ( – to connect to your email server (or SPAM Server, whichever applies) over port 25.  You will need to create an additional exception that will allow the individual NotifyLink On Demand Server to connect to your email / SPAM server.  To find the IP Address that you need to allow, simply check your firewall rules for rules that allow IMAP connections within the range of –   The source IP Address will be the same IP from which we will be sending the SMTP traffic.



PLEASE NOTE:  IMAP traffic is NOT being replaced by SMTP traffic.  The above statement should be used as a means to find the IP Address that you need to allow for SMTP traffic.


 Customers who allow external email from everyone:

 If you currently do not have any restrictions on who is allowed to send your company email, then you are not affected by this change.  The only change that you may see within your server logs is that mail will now be coming from individual On Demand Servers (hosted”x”




   1. I use NotifySync.  Am I affected by this?

 a. No.  This change ONLY affected customers who have users setup on the NotifyLink On Demand Servers.

 2. How long of a service interruption should I expect?

 a. There will not be a service interruption to your NotifyLink On Demand Service during this configuration change.

 3. I have users on multiple NotifyLink On Demand Servers.  Do I need to create an exception for each server?

 a. Yes.  Each NotifyLink On Demand Server will ONLY use its own SMTP Server.  Therefore, an exception for each server MUST be made.