How may I change the SMTP Port of my Newtest Reporting server ?

Check the port location in the Microsoft SSRS file configuration:

1- Go to "C:\Program Files\Microsoft SQL Server\MSRS10_50.NEWTEST\Reporting Services\ReportServer"

2- Edit the rsreportserver.config file

3- Find the SMTPserverPort location

4- Put the right value between <SMTPserverPort>...</SMTPserverPort>.