Send Base64 Encoded Email with PHP

Base 64 is a way to representing binary data - like images - into ASCII text. You can use use Base-64 encoding to easily send binary data through HTML Mail, e-mail attachments, JSON requests and HTML forms.

The encoded data uses A-Z, a-z, 0-9 and + and /, with = as a padding character while carriage return line feed \r\n characters are inserted into the output to keep the line lengths less than 76 characters. Here is the raw source of a MIME encoded HTML Mail:

Subject: This is a MIME encoded email
MIME-Version: 1.0
Content-Type: multipart/alternative;boundary = "Saturday16thofAugust2014081815AM"
Message-Id: <20140816081815.6ABFB2D793B0@iMac.local>
Date: Sat, 16 Aug 2014 13:48:15 +0530 (IST)

Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: base64


You can easily send MIME encoded email messages through PHP. The base64_encode() method encodes the HTML message with base64 while chunk_split() splits the encoded messages into smaller chunks and appends “\r\n” at the end.


$html = "<p>The <b>quick</b> <em>brown</em> <u>fox</u> jumped right over the lazy dog.</p><hr />";

$to   = "";
$cc   = "";
$bcc  = "";
$from = "";

$subject  = "This is a MIME encoded email";
$boundary = str_replace(" ", "", date('l jS \of F Y h i s A'));
$newline  = "\r\n";

$headers = "From: $from$newline".
           "Cc: $cc$newline".
           "Bcc: $bcc$newline".
           "MIME-Version: 1.0$newline".
           "Content-Type: multipart/alternative;".
           "boundary = \"$boundary\"$newline$newline".
           "Content-Type: text/html; charset=ISO-8859-1$newline".
           "Content-Transfer-Encoding: base64$newline$newline";

$headers .= rtrim(chunk_split(base64_encode($html)));


Amit Agarwal

Amit Agarwal

Google Developer Expert, Google Cloud Champion

Amit Agarwal is a Google Developer Expert in Google Workspace and Google Apps Script. He holds an engineering degree in Computer Science (I.I.T.) and is the first professional blogger in India.

Amit has developed several popular Google add-ons including Mail Merge for Gmail and Document Studio. Read more on Lifehacker and YourStory


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