Help / WLanguage / WLanguage functions / Communication / Managing emails
  • POP3 and SMTP protocols
  • Authenticated SMTP
  • Timeout
  • Managing emails in asynchronous mode
  • Required application feature
  • Gmail: What to do if a connection to Gmail (SMTP, IMAP, POP3) fails with a certificate error?
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Stored procedures
Starts a session for managing emails via the SMTP protocol.
Remark: To start a session for sending emails (via the SMTP protocol only), use EmailStartSMTPSession. This function can also be used to start an authenticated SMTP session.
// Management of an SMTP email session
MyEmailSMTPSession is emailSMTPSession
IF MyEmailSMTPSession.StartSession() = True THEN
UserName = MySMTPSession..Name
UserName = ""
Error("Unable to establish the connection")
<Result> = <Session>.OpenSession()
<Result>: Boolean
  • True if the session was started,
  • False otherwise. If an error occurs, the ErrorOccurred variable is set to True.
    To get more details on the error, use ErrorInfo with the errMessage constant.
<Session>: emailSMTPSession variable
Name of the emailSMTPSession variable corresponding to the email session to handle.

POP3 and SMTP protocols

The different parameters passed to <emailSMTPSession variable>.StartSession are supplied by the Internet Service Provider or by the network administrator.
An Internet connection is required to manage the emails. Several cases may occur:
  • The user uses a direct connection to Internet (cable or ADSL): no specific operation is required.
  • The user uses a modem to connect to Internet: NetOpenRemoteAccess establishes the Internet connection.
By default, if only the IP address of POP3 server is specified, this address will be used by the email server that uses SMTP. The IP address of SMTP protocol must be specified only if the POP3 account and the SMTP account do not use the same computer.

Authenticated SMTP

The SMTP authentication cannot be performed by <emailSMTPSession variable>.StartSession. To start a POP3 session and an authenticated SMTP session at the same time, you must use both EmailStartPOP3Session and EmailStartSMTPSession.


The timeout can be set using EmailSetTimeOut.
WEBDEV - Server codeAjax

Managing emails in asynchronous mode

The email functions are locking functions by default. Which means that no other code can be run during their execution. The program will resume only when the current Email functions have been run.
WEBDEV gives you the ability to manage the emails in asynchronous mode. This mode allows your sites to send emails without locking the execution of other processes.
To use the asynchronous mode, you must:
  1. Uncheck "Disable the email spooler" in the WEBDEV administrator ("Configuration" tab).
  2. Enable the asynchronous mode when starting the SMTP session (with EmailStartSMTPSession or <emailSMTPSession variable>.StartSession).
  3. All outgoing emails will be transmitted to a "spooler". Emails are queued up before being sent.
Executing Email functions does no longer block the rest of the program. EmailStatus is used to determine the status of an email.
Remark: if the WEBDEV administrator is closed, the email spooler is cleared: pending emails are not sent and are removed from the spooler.
If there are pending emails, and the "Disable the email spooler" option is checked, the emails will not be lost: the administrator continues to send them, but the spooler will not accept any new emails.
Caution: The asynchronous mode can only be used when starting a session on an SMTP server (EmailStartSMTPSession for sending emails or <emailSMTPSession variable>.StartSession). The asynchronous mode is ignored in all other cases.
Universal Windows 10 App

Required application feature

When this function is used, an application feature is declared in the application generation wizard.
Required feature: Family and corporate networks
This feature allows the applications to use incoming and outgoing accesses to the family and corporate networks.

Gmail: What to do if a connection to Gmail (SMTP, IMAP, POP3) fails with a certificate error?

Since August 2017, a new certificate was deployed by Google: Google Internet Authority G3. Unfortunately, the Windows API for checking certificates does not validate this certificate.
Therefore, starting a POP3, IMAP or SMTP session may fail with the error "The certificate string was not issued by a trusted authority".
To validate the certificate, all you have to do is modify the management mode of emails. The WLanguage EmailConfigure function allows you to change this mode and to no longer use the Windows API that locks this certificate. The following code must be added before starting the session via <emailSMTPSession variable>.StartSession:
// Enable the multi-platform implementation
EmailConfigure(emailParameterMode, 1)
Remark: From version 23 Update 1, the call to EmailConfigure is not required anymore: WLanguage is automatically using the management mode of emails adapted to the session.
Component: wd280com.dll
Minimum version required
  • Version 24
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Last update: 06/21/2023

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