Mail::Bulkmail::Server - handles server connections and communication for Mail::Bulkmail

Jim Thomason, jim@jimandkoka.com

 my $server = Mail::Bulkmail::Server->new(
        'Smtp' => 'your.smtp.com',
        'Port' => 25
 ) || die Mail::Bulkmail::Server->error();

 #connect to the SMTP relay
 $server->connect || die $server->error();

 #talk to the server
 my $response = $server->talk_and_respond("RSET");

Mail::Bulkmail::Server now handles server connections. Mail::Bulkmail 1.x and 2.x had all the server functionality built into the module itself. That was nice in terms of simplicity - one module, one connection, one server, and so on. But it had some downsides. For one thing, it only allowed for one connection. And since I wanted to allow multiple server connections in 3.00, that had to go. For another, it was a pain in the butt to change the server implementation. This way, you can easily write your own server class, drop it in here, and be off to the races.

For example, the Mail::Bulkmail::DummyServer module for debugging purposes.

This is not a module that you'll really need to access directly, since it is accessed internally by Mail::Bulkmail when it is needed. Specify the data you need in the conf file and the server_file attribute, and you won't ever need to touch this directly.

Smtp

stores the Smtp relay's address.

 $server->Smtp("your.smtp.com");

can either be an IP or a named address Smtp values should be set in your server file.

Port

stores the port on which you'll try to connect to the SMTP relay. Probably going to be 25, since that's the standard SMTP port.

 $server->Port(2);

Port values should be set in either your server file, or a single default in your conf file.

Domain

When you connect to an SMTP server, you must say hello and state your domain. This is your domain that you use to say hello.

 $server->Domain('mydomain.com');

This should be the same name of the domain of the machine that you are connecting on. Domain should be set in your conf file.

Tries

When you try to connect to an SMTP server via ->connect, you may have issues with creating the socket or making the connection. Tries specifies how many times you should re-try making the socket or making the connection before failing to connect. Make this a small number.

 $server->Tries(5);

Tries should be set in your conf file.

max_connection_attempts

This is similar to Tries, but this governs the number of times that you can call the ->connect method. When you have multiple servers in Mail::Bulkmail's ->servers array, there's no point in constantly re-trying to connect to a server that fails. it'll just slow you down. max_connection_attempts makes sure that you stop trying to connect to invalid servers. Make this a small number as well.

 $server->max_connection_attempts(7);

max_connection_attempts should be set in your conf file.

envelope_limit

It's entirely likely that with a very large list you'll have a very large number of people in the same domain. For instance, there are an awful lot of people that have yahoo addresses. So, for example, say that you have a list of 100,000 people and 20,000 of them are in the yahoo.com domain and you're sending using the envelope. That means that the server at yahoo.com is going to receive one message with 20,000 people in the envelope! Now, this might be a bad thing. We don't know if the yahoo.com mail server will actually process a message with 20,000 envelope recipients. It may or may not and the only way to find out is to try it. If it does work, then great no worries. But if it doesn't, then you're stuck. If you stop using envelope sending, you sacrifice its major speed gains, but if you keep using it you can't send to yahoo.com. envelope_limit fixes that. envelope_limit is precisely what it sounds like, it allows you to specify a limit on the number of recipients that will be specified in your envelope. That way, with our previous example, you can specify an envelope limit of 1000, for example.

 $bulk->envelope_limit(1);

This means that yahoo.com will get 20 messages, each with 1000 recipients in the envelope. Of course, this still may not be small enough, so you can tweak it as much as necessary. Setting an envelope limit does trade off some of the gains from using the envelope, but it's still over all a vast speed boost over not using it. envelope_limit should be set in your conf file. I recommend setting it to 100, but tweak it as necessary. Higher values allow you to send more information and do it faster, but you're more likely to run into server's that refuse that many recipients. Lower values are more compatible, but slightly slower. Set envelope_limit to 0 for an infinite limit. You should never have to set it below 100 (unless you're using an infinite limit), since RFC 2822 says that SMTP servers should always accept at least 100 recipients in the envelope

max_messages

max_messages sets the maximum number of messages to send to a particular server. This is mainly useful if you're bulkmailing to multiple servers. You may have a server that can take some of the load, but not much of it. Assume that your list has over 100,000 people on it, and you're using one primary SMTP relay and one smaller SMTP relay to help take some of the load off of the main one. Your primary SMTP server can handle lots of messages, but your smaller one can only take a smaller load. That'd a good place for max_messages.

 $aux_server->max_messages(1);

That way, your smaller server will relay no more than 10,000 messages. Set max_messages to 0 for an infinite number of messages to go through the server. It is recommended to set max_messages to 0.

max_messages_per_robin

when you set up your bulkmail object with multiple servers, max_messages_per_robin is used to determine how many messages are sent to a server before moving onto the next. This is the maximum number of messages that would be sent to a server in a given iteration before moving on to the next, but it is not necessarily the exact number of messages that will be sent. If the server has reached the maximum number of messages allowed, or the maximum number in a given connection, it will jump to the next server before reaching the robin limit. Set max_messages_per_robin to 0 for an infinite number of messages allowed on a given server iteration. It is recommended to set this to 500 if you're using multiple servers, and to 0 if you're using 1 server. The message robin counter is reset by reset_all_counters

max_messages_per_connection

This sets the maximum number of messages that would be sent to a given SMTP relay in a given connection. When this limit is reached, the server will disconnect and return that it has reached a limit. set max_messages_per_connection to 0 for infinite messages per connection. It is recommended to keep this at 0. The message connection counter is reset by reset_all_counters

max_messages_while_awake

Sometimes, it may be useful to pause and give your server a break. max_messages_while_awake allows this. This will specify the number of messages to send to a server before going to sleep for a certain period of time.

 $server->max_messages_while_awake(1);

Will send 100 messages to the server and then go to sleep. for the time specified by sleep_length. Note that reaching this limit will not cause reached_limit to return a true value, so in a multi-server environment, you'll end up sleeping a lot. The message-while-awake counter is reset by reset_all_counters, so it is of dubious utility when using multiple servers. Set max_messages_while_awake to 0 to never sleep. It is recommended to have max_messages_while_awake set to 0 when using multiple servers. Set it to a positive number when using one server.

sleep_length

Specifies the time to sleep (in seconds) if the server has reached the max_messages_while_awake limit.

talk_attempts

The response codes for SMTP are pretty rigorously defined, which is obviously very usefull. a 5xy error is permanently fatal. a 4xy error is temporarily fatal. It is recommended that if a 4xy error is encountered, that the client (us) should try re-sending the same command again. talk_attempts specifies the number of times to try resending a command after receiving a 400 level error from the server.

 $server->talk_attempts(5);

time_out

We can *finally* time out! So if your SMTP relay doesn't respond for a set period of time, the connection will automatically disconnect and fail with an error. Set this to something high, the value is in seconds.

 $server->time_out(3);       # 5 minutes

time_of_last_message

stores the time that the last message was sent through this server, in epoch seconds.

connected

boolean attribute that says whether or not this server object is connected to an SMTP relay. Don't set this value, only read it.

CONVERSATION

This is an optional log file to keep track of your SMTP conversations CONVERSATION may be either a coderef, globref, arrayref, or string literal. If a string literal, then Mail::Bulkmail::Server will attempt to open that file (in append mode) as your log:

 $server->CONVERSATION("/path/to/my/conversation");

If a globref, it is assumed to be an open filehandle in append mode:

 open (C, ">>/path/to/my/conversation");
 $server->CONVERSATION(\*C);

if a coderef, it is assumed to be a function to call with the address as an argument:

 sub C { print "CONVERSATION : ", $_[1], "\n"}; #or whatever your code is
 $server->CONVERSATION(\&C);

if an arrayref, then the conversation will be pushed on to the end of it

 $server->CONVERSATION(\@conversation);

Use whichever item is most convenient, and Mail::Bulkmail::Server will take it from there. Be warned: This file is going to get huge. Massively huge. You should only turn this on for debugging purposes and never in a production environment. It will log the first 50 characters of a message sent to the server, and the full server response.

socket

socket contains the socket that this Server has opened to its SMTP relay. You'll probably never talk to this directly, but it's here, just in case you want it.

increment_messages_sent

This method will increment the server object's internal counters storing the total number of messages sent, the total sent this robin, the total sent this connection, the total sent while awake, and the total sent this envelope. It will also store the time the last message is sent.

reset_message_counters

This message will reset the internal counters for the messages sent this robin, messages sent this connection, and messages sent while awake back to 0.

reset_envelope_counter

The envelope counter behaves slightly differently than the other counters, so we have a separate method to reset the internal envelope counter.

reached_envelope_limit

This method returns 1 if we've reached the envelope limit, 0 otherwise

reached_limit

This method will tell you if the server has reached the max_messages, max_messages_per_connection, or max_messages_per_robin limits. Also, if you reach the max_messages_while_awake limit, this method will cause you to sleep for the time period specified in sleep_length

 Return values:
 1 : reached max_messages limit, server becomes worthless and will not be used again
 2 : reached max_messages_per_connection limit, server will disconnect
 3 : reached max_messages_per_robin limit

new

Standard constructor. See Mail::Bulkmail::Object for more information.

connect

Connects this server object to the SMTP relay specified with ->Smtp and ->Port This method will set ->connected to 1 if it successfully connects.

 $server->connect() || die "Could not connect : " . $server->error;

Upon connection, ->connect will issue a HELO command for the ->Domain specified. This method is known to be able to return:

 MBS001 - cannot connect to worthless servers
 MBS002 - could not make socket
 MBS003 - could not connect to server
 MBS004 - no response from server
 MBS005 - server won't say HELO
 MBS010 - can't greet server w/o domain
 MBS011 - server gave an error for EHLO
 MBS015 - timed out waiting for response upon connect
 MBS016 - server didn't respond to EHLO, trying HELO (non-returning error)
 MBS017 - cannot connect to server, no Tries parameter

disconnect

disconnects the server object from the SMTP relay. Before disconnect, it will issue a RSET and then a quit command to the SMTP server, then close the socket. disconnect sets ->connected to 0. disconnect can also disconnect quietly, i.e., it won't try to issue a RSET and then quit before closing the socket.

 $server->disconnect();                         #issues RSET and quit
 $server->disconnect('quietly');        #issues nothing

talk_and_respond

talk_and_respond takes one argument and sends it to your SMTP relay. It then listens for a response.

 my $response = $server->talk_and_respond("RSET");

If you're not connected to the relay, talk_and_respond will attempt to connect. This method is known to be able to return:

 MBS006 - cannot talk w/o speech
 MBS007 - cannot talk to server
 MBS008 - server won't respond to speech
 MBS009 - server disconnected
 MBS012 - temporarily won't respond to speech...re-trying
 MBS013 - could never resolve temporary error
 MBS014 - timed out waiting for response
 MBS018 - No file descriptor

create_all_servers

create_all_servers will iterate through the file specified in server_file in the conf file and return an arrayref of all server objects created.

 define package Mail::Bulkmail::Server

 server_file    = ./server_file.txt

your server file should be of the format of another Mail::Bulkmail conf file, containing definitions for all of the SMTP servers you want to use. See the examples below for how to set up the conf files. If you would like to specify a different conf file, pass that as an argument.

 my $servers = Mail::Bulkmail::Server->create_all_servers('/path/to/new/server_file.txt');

This will then ignore the server_file in the conf file and use the one passed. You may also pass hashrefs of init data for new servers.

 my $servers = Mail::Bulkmail::Server->create_all_servers(
        {
                'Smtp' => 'smtp.yourdomain.com'
        },
        {
                'Smtp' => 'smtp2.yourdomain.com'
        },
        {
                'Smtp' => 'smtp3.yourdomain.com'
        }
 ) || die Mail::Bulkmail::Server->error;

This is called internally by Mail::Bulkmail's constructor, so you probably won't ever need to touch it.

It is recommended that you define your server entries in your server file. See Mail::Bulkmail::Object and Mail::Bulkmail for more information on conf file set up and how to define your server_file.

 #in your conf file, you want this
 define package Mail::Bulkmail::Server

 #your server file
 server_file = /etc/mb/server.file.txt

Now, your server file should look like this:

 define package Mail::Bulkmail::Server

 #set up the first server
 Smtp @= smtp1.yourdomain.com
 Port @= 25
 Tries @= 5
 max_messages_per_robin @= 1000
 envelope_limit @= 100

 #set up the second server
 Smtp @= smtp2.yourdomain.com
 Port @= 25
 Tries @= 5
 max_messages_per_robin @= 1000
 envelope_limit @= 100

 #set up the third server
 Smtp @= smtp3.yourdomain.com
 Port @= 25
 Tries @= 5
 max_messages_per_robin @= 1000
 envelope_limit @= 100

Alternatively, you can use defaults in your master conf file.

 #your server file
 server_file = /etc/mb/server.file.txt

 #These values will apply to all servers
 Port = 25
 Tries = 5
 max_message_per_robin = 1000
 envelope_limit = 100

Now, your server file should look like this:

 define package Mail::Bulkmail::Server

 #set up the first server
 Smtp @= smtp1.yourdomain.com

 #set up the second server
 Smtp @= smtp2.yourdomain.com

 #set up the third server
 Smtp @= smtp3.yourdomain.com

Be warned that if you want to set up a value for one server, you should set it up for all of them. Either specify the attribute for a server in the master conf file, or specify it multiple times for all servers.

Mail::Bulkmail, Mail::Bulkmail::DummyServer

Copyright and (c) 1999, 2000, 2001, 2002, 2003 James A Thomason III (jim@jimandkoka.com). All rights reserved. Mail::Bulkmail::Server is distributed under the terms of the Perl Artistic License.

So you don't have to scroll all the way back to the top, I'm Jim Thomason (jim@jimandkoka.com) and feedback is appreciated. Bug reports/suggestions/questions/etc. Hell, drop me a line to let me know that you're using the module and that it's made your life easier. :-)