TreeFrog Framework incorporates a mailer (mail client) which makes it possible to send mails by SMTP. For now (v1.0), only SMTP message sending is possible. To create mail messages, an ERB template is used.

First, let’s create a mail skeleton with the following command:

 $ tspawn mailer information send
   created  controllers/informationmailer.h
   created  controllers/informationmailer.cpp
   created  controllers/
   created  views/mailer/mail.erb

The class of InformationMailer is created in the controller directory, and the template with the name mail.erb is created in the views directory.

Next, open the mail.erb that was previously created and then change its content to the following:

 Subject: Test Mail
 To: <%==$ to %>

 This is a test mail.

Above the blank line is the mail header, and below is the content of the body. Specify subject and destination in the header. It is possible to add any field of header. However, Content-Type and Date field are automatically added, so that you don’t need to write them there.

If you are using multi-byte characters, such as Japanese, save the file by setting the encoding (default UTF-8) in the settings file of InternalEncoding.

Call the deliver() method at the end of the send() method of the InformationMailer class.

void InformationMailer::send()
    QString to = "";
    deliver("mail");   // ← mail.erb Mail sent by template

You are now able to call from outside of the class. By writing the following code in the action, the process of mail sending will be executed:

  • When you actually send a mail, please see the following “SMTP Settings” section.

When you need to send a mail directly without using a template, you can use the TSmtpMailer::send() method.

SMTP Settings

There is no configuration information for SMTP in the code above. It becomes necessary to set information about SMTP in the application.ini file.

# Specify the connection's host name or IP address.

# Specify the connection's port number.

# Enables SMTP authentication if true; disables SMTP
# authentication if false.

# Specify the user name for SMTP authentication.

# Specify the password for SMTP authentication.

# Enables the delayed delivery of email if true. If enabled, deliver() method
# only adds the email to the queue and therefore the method doesn't block.

If you use SMTP authentication, you need to set this:


As for the authentication method, CRAM-MD5, LOGIN and PLAIN (using this priority) are mounted in a way, so that the authentication process is performed automatically.

In this framework, SMTPS email sending is not supported.

Delay sending the mail

Since mail sending by SMTP needs to pass the data through an external server, it requires time compared to the process. You can return an HTTP response before the mail sending process is executed.

Edit the application.ini file as follows:


By doing this, the deliver() method will be a non-blocking function of merely queuing data. The mail sending process will occur after returning an HTTP response.

Additional note: If you don’t set the delay sending (in case of false), the deliver() method would keep blocking until the SMTP processing ends, or all ends up in an error.