Send PHP HTML mail with attachments

Question

I got a problem: Until today, I sent HTML mails with PHP using a header which contains

Content-type: text/html;

Now, I added functionality

Answer 1

To send an email with attachment we need to use the multipart/mixed MIME type that specifies that mixed types will be included in the email. Moreover, we want to use multipart/alternative MIME type to send both plain-text and HTML version of the email.Have a look at the example:

 
--PHP-mixed-  
Content-Type: multipart/alternative; boundary="PHP-alt-" 

--PHP-alt-  
Content-Type: text/plain; charset="iso-8859-1" 
Content-Transfer-Encoding: 7bit

Hello World!!! 
This is simple text email message. 

--PHP-alt-  
Content-Type: text/html; charset="iso-8859-1" 
Content-Transfer-Encoding: 7bit

Hello World!
 
This is something with HTML formatting.
 

--PHP-alt--- 

--PHP-mixed-  
Content-Type: application/zip; name="attachment.zip"  
Content-Transfer-Encoding: base64  
Content-Disposition: attachment  

 
--PHP-mixed--- 

As you can see, sending an email with attachment is easy to accomplish. In the preceding example we have multipart/mixed MIME type, and inside it we have multipart/alternative MIME type that specifies two versions of the email. To include an attachment to our message, we read the data from the specified file into a string, encode it with base64, split it in smaller chunks to make sure that it matches the MIME specifications and then include it as an attachment.