Ubuntu Manpage: postal - program to test SMTP mail server throughput.

NAME

       postal - program to test SMTP mail server throughput.

SYNOPSIS

       postal  [-m maximum-message-size] [-M minimum-message-size] [-t threads] [-c messages-per-connection] [-r
       messages-per-minute]  [-s  ssl-percentage]  [-L]  [-l  local-address]  [-a]  [-b  [no]netscape]   [-[z|Z]
       debug-file] [-f sender-file] smtp-server user-list-filename

DESCRIPTION

This manual page documents briefly the postal program.

It is designed to test the performance of SMTP email servers by sending random messages to the specified
server as fast as possible.

The smtp-server parameter specifies the IP address or name of the mail server that the mail is to be sent
to. Mail sent by Postal will not use MX records, this is to allow testing outbound relays etc. If you
want to specify a port other than port 25 then enclose the host address in square brackets and have the
port address immediately following. If you want a DNS lookup for every connection (for testing
round-robin DNS) then immediately precede the host address with a '+' character. To specify multiple
servers for round-robin use then separate the addresses with commas. Note that localhost is used for
connecting to the same machine.

The user-list-filename is the name of a file which contains a list of user's email addresses. This can
be just user-names or fully qualified email addresses. Whatever you specify will be sent exactly in the
SMTP protocol so make sure you do whatever is appropriate. If unsure then use fully qualified addresses
(IE user@example.com).

The sender-file contains a list of users that will be in the From: field and envelope sender of the
messages. If it is not specified then the user-list-filename will be used for the sender list.

The maximum-message-size indicates the size in Kilobytes that will be the maximum size of the message
body. The size of each message body will be a random number between 0 and the maximum size. Specify "0"
if you want just headers to test the connection rate. The default value is 10.

The threads parameter is the number of threads that should be created to attempt separate connections. A
well configured mail server won't accept an unlimited number of connections so make sure you don't
specify a number larger than the number your mail server is configured to handle. Also for sensible
results make sure that you don't use enough to make your server thrash as the results won't be
representative of real-world use. The default value is 1, this default is not suitable for real tests,
it's just for testing your configuration. If you specify multiple server addresses for round-robin use
then this number of threads will be created per server, IE 4 servers and -p5 will give 20 threads total.

The messages-per-connection parameter is for sending more than one message per SMTP connection. The
default value is "1". A value of -1 means to send an indefinite number of messages on one connection (~4
billion). If a value > 1 is specified then the number sent on each connection is a random number between
1 and the number specified. For simulating a mail server connected directly to the net use a value of 2
or 3. For simulating a mail server connected to a front-end relay use a large number. For testing for
bugs in your mail server use the value 0 and leave it running for a week. ;) A value of 0 means to
disconnect without sending any messages. Good for testing a LocalDirector.

The max-messages-per-minute parameter is for limiting the throughput of the program. This is designed to
be used when you want to test the performance of other programs when the system is under load. The
default is effectively 24000 messages per minute.

The local-address parameter specifies which local IP address(es) are used to make the outbound
connections. Specified in the same way as the remote address. This is good for testing LocalDirectors
or other devices that perform differently depending on which source IP address was used.

The -L command specifies that LMTP is to be used instead of SMTP.

The -a command turns on all logging. All message data received will be logged. This will make it slow
and it may not be able to saturate a fast Ethernet link...

The -b switch allows you to specify breakage strings. Currently the only option is for Netscape mail
server which strips spaces from the start of subject lines. -b netscape means to avoid leading spaces on
subject fields to not break Netscape. -b nonetscape means to always put extra space to test for the bug
in Netscape and similar products. Some people say that the RFCs are open to interpretation on this
issue, I am interested to see whether anyone else interprets it the way that Netscape does.

The -s switch specifies the percentage of connections which are to use TLS AKA SSL. Use 0 for no SSL, or
100 for always SSL, or any number in between. Default is 0.

The -z switch allows you to specify a debugging file base. From this base one file is created for each
thread (with a ':' and the thread number appended), each file is used to log all IO performed by that
thread for debugging purposes.

The -Z switch is the same but creates a separate file for each connection as well with an additional ':'
appended followed by the connection number.

NOTES

       When  testing  mail  servers  please  use  domains defined in http://www.rfc-editor.org/rfc/rfc2606.txt -
       example.com, example.net, and example.org
        are all good options.  Please don't use anything related to a valid name, since that will cause pain for
       you and others on the net.

RETURN CODES

       0      No Error

       1      Bad Parameters

       2      System Error, lack of memory or some other resource

AUTHOR

       This  program,  it's  manual  page,  and   the   Debian   package   were   written   by   Russell   Coker
       <russell@coker.com.au>.

AVAILABILITY

       The source is available from http://doc.coker.com.au/projects/postal/ .

       See http://etbe.coker.com.au/category/benchmark for further information.