How to use an external SMTP server for sending emails

Why is this feature needed ?

MailBoy has a built-in SMTP server for sending the messages directly from your PC to the recipient’s mail server (without using any ISP SMTP server). This is the fastest and preferable method for sending email messages.

However for the correct work of the program, you need to have access to port 25.

If you’re operating within a restrictive firewall, as most users of large ISPs do, then you won’t be able to use MailBoy’s built-in SMTP for sending the messages, because of the blocking of port 25.

Most of free ISP’s such as Juno, WorldShare, EarthLink, NetZero, and others block the port 25 and will only allow you to send email using their email servers. In this case you will need to use the SMTP server of your Internet Service Provider to deliver your message.

This is why we’ve implemented in MailBoy the ability to use an external SMTP server for sending the messages.

How it works ?

First, MailBoy sends a message to the external SMTP server. This server puts your email in outgoing message queue, the message is sent to your correspondent’s mail server. And only after that, your correspondent can receive it.

If the server is not overloaded, delivering a message takes just a few seconds. But this also might take a longer time.

When to use it ?

If your messages failed to send you have tried everything described in this article,
and still no success sending a message out. Then it is most likely that your ISP is blocking port 25 and you have to use an external SMTP server in order to be able to send messages.

How to use this feature ?

You can set the usage of an external SMTP server from the Options dialog of the program:

  1. Check the option “Use external SMTP server to deliver the messages”
  2. For “SMTP server” fill the address of your ISP’s SMTP server. If you don’t know it, please asko your ISP about it.
  3. Set the “Port” to 25, except if your ISP have stated some other port for using its SMTP server. In that case, fill the value required by your ISP.
  4. If the external SMTP server requires authentication, then check the option “This SMTP server requires authentication” and fill your user name in the “Login” field and your password in the “Password” field.

This is it. You are now ready to send the messages using an external SMTP server. If you want to switch back to using the program’s built-in SMTP server, just uncheck the “Use external SMTP server to deliver the messages” option from the Options dialog.


Set the optimal Threads Count

More of the ISPs will not allow you to send high volume email campaigns through their SMTP servers, because they have set sending limits. The limit could be the number of messages allowed to be send within an hour or a day, etc. So, be sure not to set high value for the Threads Count (in the Options dialog). This way you will also prevent oveloading of the SMTP server.

If your mail list is less than 1000 or few thousands, the best is to set the Threads Count within the 1-5 range. Don’t worry, the messages will be sent fast enough, except if the SMTP server is currently busy (or overloaded).