Die wichtigszen Ports

The following TCP ports are used in the most common email protocols:
- TCP port 25: The default port used in SMTP for non-encrypted communications.
- TCP port 465: The port registered by the Internet Assigned Numbers Authority (IANA) for SMTP over SSL (SMTPS). SMTPS has been deprecated in favor of STARTTLS.
- TCP port 587: The Secure SMTP (SSMTP) protocol for encrypted communications, as defined in RFC 2487, using STARTTLS. Mail user agents (MUAs) use TCP port 587 for email submission. STARTTLS can also be used over TCP port 25 in some implementations.
- TCP port 110: The default port used by the POP3 protocol in non-encrypted communications.
- TCP port 995: The default port used by the POP3 protocol in encrypted communications.
- TCP port 143: The default port used by the IMAP protocol in non-encrypted communications.
- TCP port 993: The default port used by the IMAP protocol in encrypted (SSL/TLS) communications.

NetBIOS-related operations use the following ports and protocols:
- TCP port 135: Microsoft Remote Procedure Call (MS-RPC) endpoint mapper, used for client-to-client and server-to-client communication
- UDP port 137: NetBIOS Name Service
- UDP port 138: NetBIOS Datagram Service
- TCP port 139: NetBIOS Session Service
- TCP port 445: Server Message Block (SMB) protocol, used for sharing files between different operating system, including Windows and Unix-based systems