Setting multiple SMTP settings in web.config?

Question

I am building an app that needs to dynamically/programatically know of and use different SMTP settings when sending email.

I\'m used to using the system.net/mailSet

Answer 1

This is how i use it and it works fine for me (settings are similar to Mikko answer):

1. First set up config sections:

   <configuration>
     <configSections>
       <sectionGroup name="mailSettings">
         <section name="default" type="System.Net.Configuration.SmtpSection" />
         <section name="mailings" type="System.Net.Configuration.SmtpSection" />
         <section name="partners" type="System.Net.Configuration.SmtpSection" />
       </sectionGroup>
     </configSections>
   <mailSettings>
     <default deliveryMethod="Network">
       <network host="smtp1.test.org" port="587" enableSsl="true"
              userName="test" password="test"/>
     </default>
     <mailings deliveryMethod="Network">
       <network host="smtp2.test.org" port="587" enableSsl="true"
              userName="test" password="test"/>
     </mailings>
   <partners deliveryMethod="Network">
     <network host="smtp3.test.org" port="587" enableSsl="true"
              userName="test" password="test"/>
   </partners>
   

2. Then it would be the best to create a some sort of wrapper. Note that most of code below was taken from .NET source code for SmtpClient here

   public class CustomSmtpClient
   {
       private readonly SmtpClient _smtpClient;
   
       public CustomSmtpClient(string sectionName = "default")
       {
           SmtpSection section = (SmtpSection)ConfigurationManager.GetSection("mailSettings/" + sectionName);
   
           _smtpClient = new SmtpClient();
   
           if (section != null)
           {
               if (section.Network != null)
               {
                   _smtpClient.Host = section.Network.Host;
                   _smtpClient.Port = section.Network.Port;
                   _smtpClient.UseDefaultCredentials = section.Network.DefaultCredentials;
   
                   _smtpClient.Credentials = new NetworkCredential(section.Network.UserName, section.Network.Password, section.Network.ClientDomain);
                   _smtpClient.EnableSsl = section.Network.EnableSsl;
   
                   if (section.Network.TargetName != null)
                       _smtpClient.TargetName = section.Network.TargetName;
               }
   
               _smtpClient.DeliveryMethod = section.DeliveryMethod;
               if (section.SpecifiedPickupDirectory != null && section.SpecifiedPickupDirectory.PickupDirectoryLocation != null)
                   _smtpClient.PickupDirectoryLocation = section.SpecifiedPickupDirectory.PickupDirectoryLocation;
           }
       }
   
       public void Send(MailMessage message)
       {
           _smtpClient.Send(message);
       }
   

   }

3. Then simply send email:

   new CustomSmtpClient("mailings").Send(new MailMessage())

Answer 2

It seems that you can initialize using different SMTP strings.

SmtpClient client = new SmtpClient(server);

http://msdn.microsoft.com/en-us/library/k0y6s613.aspx

I hope that is what you are looking for.