the best 3 season tents generally come with a waterproof rain fly and a breathable canopy ideally you want to find a three season tent with a waterproof floor the rugged bathtub floor is generally reserved for the more expensive four season tent but not always
The default port number of an outgoing SMTP server is  25: but a switch to another one can be needed: for instance, if you are facing issues with the SMTP connection (the client is not sending emails even if the server name is right) you can try to change the port as a troubleshooting measure.
Well known ports are from 0 to 1023(total 2^10=1024 ports) Default port is a designated port for particular well-known service such as web server, mail server, ftp server etc. By default FTP uses 21 port, DNS uses 53 and Apache uses 80 port.