PowerPoint Presentation

Sending Bulk Email Using PHP

BySudheer Satyanarayanahttp://techchorus.net

Table Of Contents

Bulk email challenges

Tools and techniques

Best practices

Sample code

Question and answers

Challenges

User's expectations

Outgoing emails restrictions set by hosting providers

Incoming email filters set by recipient servers and their users

Compliance - legal and tacit agreements

Avoiding getting blacklisted

Prerequisites

Opt-in list

Own email server for full blown solution

Servers are becoming less expensive

Amazon - $0.085 per hour / INR 3.99 per hour

Rackspace Cloud - 1.5 per hour / INR 0.7 per hour

Identity And Branding

Use dedicated public static IP address

Have correct reverse DNS record for your IP address

Have up to date contact information in WHOIS record

Monitor postmaster and abuse mailboxes

Have a consistent from header

Have SPF records

Sign messages using DKIM

Identity And Branding - Reverse DNS

Forward DNS lookup maps domain name to an IP address

Reverse DNS lookup maps IP address to a domain

Server hosting providers offer a way to set the reverse DNS entry in their control panels

Example

31.41.51.61 pointing to myserver.example.com

Headers

Email contains two major sections

HeaderHeader sections fieldsExample fields - From, To, Subject, Date, Message-Id

BodyUnstructured

Sample Email With Headers

Use A PHP Library

Prefer SMTP over sendmailPopular PHP libraries that support SMTP

Zend Framework - Zend_Mail

PHPMailer

Swift Mailer

Zend_Mail Sample Usage

Configure SMTP Before You Send.Use this snippet if SMTP authentication is not required

$config = array('name' => 'myserver.example.com');$transport = new Zend_Mail_Transport_Smtp('myserver.example.com', $config);

Zend_Mail_Transport_Smtp('myserver.server.com', $config); Zend_Mail::setDefaultTransport($transport);

Zend_Mail Sample Usage

Use this snippet if SMTP authentication is required

$config = array( 'auth' => 'login', 'username' => 'myusername', 'password' => 'password');$transport = new Zend_Mail_Transport_Smtp('myserver.server.com', $config); Zend_Mail::setDefaultTransport($transport);

Zend_Mail Sample Usage

$mail = new Zend_Mail();$mail->setBodyText('Hello World!');$mail->setFrom('you@example.com', 'You');$mail->addTo('me@example.com', 'Me');$mail->setSubject('Greetings');$mail->send();

From, To, Subject headers are automatically set by Zend_Mail.

Zend_Mail also handles MIME encoding.

Identity And Branding - SPF Record

Sender Policy Framework

Email Validation System

Have a text DNS record and publish your policy

Recipient servers validate sender by reading your DNS record

SPF Example:"v=spf1 ip4:192.168.0.1/16 -all"Allow any IP address between 192.168.0.1 and 192.168.255.255.Use the SPF record generatorhttp://old.openspf.org/wizard.html

Identity And Branding - DKIM

DomainKeys Identified Mail

A method for email authentication

Public key cryptography

Example HeaderDKIM-Signature: d=example.com s=myserver b=MTI...I=;

List Management - Subscribing

Let users explicitly opt in to your lists

Verify the subscriber's email address

Consider double opt in

Avoid purchasing lists

Send subscription reminders to users. Offer methods to unsubscirbe from the lists the user may no longer be interested in.

List Management - Unsubscribing

A link in every email. Do not ask the user to login to unsibscribe

Do not force the user to fill in 'reason' field in the unsubscribe form field. Use unsubscribe form only for confirmation.

Provide a 'List-Unsubscribe' header

Automatically unsubscribe users whose addresses have reached a bounce threshold. Use VERP.

List Management - Unsubscribing

List-Unsubscribe Header

$mail = new Zend_Mail();$mail->setBodyText('Hello World!');$mail->setFrom('you@example.com', 'You');$mail->addTo('me@example.com', 'Me');$mail->setSubject('Greetings'); $mail->addHeader('List-Unsubscribe', 'mylist-unsubscribe@my.example.com');$mail->send();

List Management - Unsubscribing

List-Unsubscribe Header With Unique Identifier

$mail->addHeader('List-Unsubscribe', 'mylist-unsubscribe+myuniqueidentifier@my.example.com');

List Management - Unsubscribing

Return-Path Header

Return-Path header's value is usually same as From

Depends on your email server setting

When an email is bounced the details are sent to the email address specified in the Return-Path header

Return-Path: me@my.example.comFrom: me@my.example.com

List Management - Unsubscribing

VERP - Variable envelope return path

Automatic Bounce Handling

Make use of Return-Path header

Return-Path: me+specially_encoded_recipients_email@my.example.com

Server must support VERP

List Management - Unsubscribing

Without VERPReturn-Path: me@my.example.comWith VERP

Return-Path: me+you=you.example.com@my.example.com

Use POP to fetch mails of me@my.example.com and parse the Return-Path header.

List Management - Unsubscribing

Automatic Bounce Handling - VERP

Fetching mail using POP$mail = new Zend_Mail_Storage_Pop3(array( 'host' => 'localhost', 'user' => 'test', 'password' => 'test'));foreach ($mail as $messageNumber=>$message) {$headers = $message->getHeaders();$to = $headers['to'];//... }

Delivering To Inbox

Ask the user to add your email address set in the from header to their address books

If falsely flagged as SPAM, ask the users to flag the email as not SPAM

Use separate from email address for transactional emails and promotional emails

Use separate IP address for transactional emails and promotional emails

Use separate domains for transactional emails and promotional emails

Settings To Administer The Program

Number of outgoing emails per hour

Number of outgoing emails per hour per domain

List of blacklisted domains

Delay between outgoing emails

Process bounce handling every __ hours

Bounce treshold

Tips And Tricks

Log every action

Respond to user's complaints

Apply for whitelists when you have a problem

Sample entitiessubscriber - email, preferred format, namelist - namelist_subscriber - lookup table. One subscriber can belong to many lists.message - subject, text body, HTML bodymessage_queue - subscriber_id, message_id, list_id, sent, sent_time, unique_identifier

Thank You

Contact - sudheer.s@sudheer.nethttp://techchorus.nethttp://projects.binaryvibes.co.in/projects/show/barehttp://projects.binaryvibes.co.in/projects/show/bizsensehttp://binaryvibes.co.in

Licence

Sending Bulk Email Using PHP by Sudheer Satyanarayana is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 2.5 India License.
Based on a work at techchorus.net.
Permissions beyond the scope of this license may be available at http://techchorus.net.