How to redirect all SmarterMail webmail domains to one secure domain using IIS 7 and above
**This article assumes that you already have an SSL certificate installed on your mail server.
Let's assume you purchased an SSL certificate for your main email domain in SmarterMail. We will call the domain mail.securedomain.com. Let's also assume that you have x number of other domains in Smartermail. We will call them mail.domain1.com, mail.domain2.com and so on. This article is going to explain how to get mail.domain1.com, mail.domain2.com etc... to automatically redirect to https://mail.securedomain.com.
1.) Log into your SmarterMail admin interface and make sure all of your domains in SmarterMail are using the same IP address.
2.) On your server, go to C:\inetpub\wwwroot\aspnet_client\system_web\4_0_30319 and create a folder called SMSSLRedirect (You can actually name this folder anything you like)
3.) Open IIS and create a new website called SM Redirect and point the home directory to the path in step 1. Edit the bindings for this site. For Type choose "http", for IP address choose "All Unassigned" and for port, choose "80". Click OK.
4.) Click your SM Redirect site in IIS and on the right, double-click the "Http Redirect" icon.
5.) Put a check in the box which says "Redirect requests to this destination". In the box type https://mail.securedomain.com.
6.) Put a check in the box which says "Only redirect requests to content in this directory (not subdirectories). Make sure the status code is 302. Click Apply on the upper right.
7.) Right-click your SmarterMail site on the left and edit bindings.
8.) If you have anything in this area, remove it and add a new binding. For Type choose "https", for hostname enter mail.securedomain.com, for IP address choose "All Unassigned" and for port, choose "443", for SSL Certificate, choose the correct SSL. Click OK.
This is all you need to do. Test by going to mail.domain1.com in a browser and it will automatically redirect to https://mail.securedomain.com.