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Question about SMTP and Delphi

Hi, i have a few questions about SMTP, I am currently using NMSMTP to send email with my app but i'm having some problems,
When my program cant get a connect with a SMTP server, it gives an error
"Null remote address" on the invalid host event, i need to make that error message go away, and make it do a loop trying to get a connect by  appendding mail. or smtp. ,gate. ect.  to the target domain (that i'm sending mail to) and will that send an e-mail? can i put mx1. or something, Please Help, basically i need something to get a connect if my program cant find local smtp server.
1 Solution
herd_boneAuthor Commented:
sorry about the points i'm out
what smtp server adress do u use then? can u ping it?


First of all, may I recommend that you look at


The product is free for use (including commercial applications) as long as you credit them somewhere in the application (splash screen etc).
The product is reasonably stable, was included as part of Delphi 7 that I use, and I do use it in commercial applications.
Is available for Delphi 5 - 8.

With NMSMTP, whilst my memory is a bit hazy, I was not happy with it, and many others have expressed similar views (mainly timing issues).

I have included working code using the Indy components. You can use it with the Indy tools if you decide to install them, or just to review and correlate back to the requirements of the library that you wish to use.

///////////////////// CODE using Delphi 7 and Indy Components ////////////////////////////

Procedure ????????????????????????? //usually from an event like a button click

   // the main variables that you will modify for each message
    messagememo.lines.add('your message text');
    messagememo.lines.add('more text if you need it');
    emailaddress := 'johnsmith@somedomain.com');

// standard message variables required
with Idmessage1 do
         From.Text := 'yourname@yourdomain.com';
         ReplyTo.EMailAddresses := 'yourname@yourdomain.com';
         Recipients.EMailAddresses := emailaddress; { To: header }
         Subject := 'Subject of the message goes here'; { Subject: header }
  //       Priority := TIdMessagePriority(cboPriority.ItemIndex); { Message Priority }
         CCList.EMailAddresses := ''; {CC}
         BccList.EMailAddresses := ''; {BBC}
         ReceiptRecipient.Text := '';

//smtp authentication - first two lines.....smtp standard requirements - next two lines
idSMTP1.Username := 'yourmailloginname'; //usually your pop3 mail login
idSMTP1.Password := 'yourmailloginpassword'; //usually your pop3 password
idSMTP1.Host := 'mail.yourdomain.com'; // if you are with an ISP, normally mail.ISPDomain.com (e.g. mail.earthlink.com)
idSMTP1.Port := 25;
{now we send the message}

That is about as simple as an smtp sending app as you can get. You can put more code in to trap errors, but for this purpose, lets keep it simple.
Just make sure that you have the idMESSAGE (indy misc) and idSMTP (indy clients)  components on the form.

One of the things that may be causing you an issue, is that some ISP's have protection (from spam, relaying etc), that requires you actually access the pop server first, before they let you send (most mail clients do it this way round normally). The way around this, is providing authentication to the SMTP server (usually your normal mail login and password), and this does not require you to perform a pop3 receive first.

As you can see in the code, I have setup SMTP authentication, and there is no harm in always adding this anyhow.

I hope this helps a little.....


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