The following routing options are available:

• Smart host   This option designates a server through which to route all outgoing messages.
  
  
• Maximum hop count   This option determines the maximum number of servers that a message is routed through before it is considered undeliverable.
  
  
• Fully qualified domain name   This option clarifies the address to use in mail exchange (MX) records.
  
  

The following transmission options are available:

• Retry intervals   This option determines how many times to resend a message, and at what intervals, before the message is considered undeliverable.
  
  
• Delay notification   This option determines how long the message is in retry before a notification is sent to the sender of the message.
  
  
• Expiration timeout   This option determines how long the SMTP service will continue to try to deliver a message before the message is considered undeliverable.
  
  

The following security options are available:

• Outbound security   This option lets you use authentication and Transport Layer Security (TLS) encryption for outgoing messages.
  
  
• Reverse DNS lookup   This option verifies that the message actually originated from the computer and the domain listed in the From field.
  
  
• Masquerade domain   This option replaces any local domain name used in any Mail From lines in the protocol with a different domain name. This is the name that you want stamped on outgoing messages.