Update configure-send-emails.md

[Tome-Lopes]

Following up on Jira GSSA-1294 and validating with Cloud Lead Luis Rosa, we concluded that we should add information on OutSystems supported SMTP ports and mention the port 25 throtle. Please feel free to review the format and position of this addition.

[OS-gayathrikrishnaswamy]

@outsystemsbot cla approve