Hello Elena,
please sure that your SMTP server is correctly configured.

An SMTP server is used for outgoing mail. The Email SMTP Server setting in the Email and Conferences module is where you should enter the log-in details for your SMTP account.
This will allow the Gateway to log in so that it can send your external mail.

Working on the data server machine or having connected using a normal client, use the [Switch Module] button in the Navigation Centre to ensure you are in the Email and Conferences module, and then open the Email SMTP Server setting from the 'Settings' list.