Hi Iris,
Can you give the log messages for more context.
Thanks
Hello,
I’m considering the configuration is not on-premise.
Can you try executing this command from your Mendix server, To see if your email server is accessible from a Mendix server? "telnet smtp.gmail.com 465" (replace server name and port with the one that corresponds to your configuration).
Contact the firewall management team if this command doesn't work so they can assist you in configuring ports as needed.
You said, "I used the same settings for the email with templates module, which work fine in all scenario". However, I cannot think of any reason why send email wouldn't work with Email Connector.