The sendmail program offers a verbose mode of operation. In this "blow-by-blow" mode, a description of all the sendmail program's actions is printed to the standard output. This mode is valuable in running sendmail interactively but must not be used when running in daemon mode. Consequently, you should never set this option in the sendmail.cf file. Instead, you should set it from the command line using the -v command-line switch.

After the sendmail.cf file is parsed and the command-line arguments have been processed, sendmail checks to see whether it is in verbose mode. If it is, it sets the HoldExpensive option (don't connect to expensive mailers, HoldExpensive) to false and sets the DeliveryMode option (DeliveryMode) to interactive.

The forms of the Verbose option are as follows:

-v             command-line shorthand 
O Verbose=bool configuration file (V8.7 and later) 
-OVerbose=bool command line (V8.7 and later) 
Ovbool         configuration file (deprecated) 
-ovbool        command line (deprecated) 

The argument bool is of type Boolean. If it is missing, the default value is true (be verbose). If the entire option is missing, the default value is false (be quiet).

Note that setting restrictexpand (See this section), with the PrivacyOptions option, disables this Verbose option.

The Verbose option is safe. When it is specified from the command line, sendmail retains its special privileges. Note that the Verbose option should never be set in the configuration file.