Windows SMTP
Open Passwork web interface and go to Settings and Users → System Settings → Notifications.
Activate the Send email notifications option and in Email service use Local service, specify the sender's email and save the changes:

Open PowerShell as "Administrator":
Install an SMTP server:
Enable autostart of the smtpsvc service:
Open Server Manager → Tools → Internet Information Services (IIS) 6.0 Manager:

Open SMTP Server — Properties:

Go to Delivery → Advanced and fill in the Smart host. For the example Gmail is used and it is necessary to specify — smtp.gmail.com:

In Outbound connections, set port 587 for TCP:

In Outbound Security, execute:
- Select — Basic authentication;
- Fill in — User name and Password;
- Enable — TLS Encryption.

Open the Access section, in the Connection control setting, add the IP address 127.0.0.1 to the list of allowed IP addresses:

In the Relay restrictions section, add the IP address 127.0.0.1 to the list of allowed IP addresses:

The SMTP server configuration is complete.