WSO2 EI Send Email as Attachment From base64 String - email

Question

I am using WSO2 EI 6.5.0 to send email with attachment. Is it possible to send an HTML email with attachment while the attachment is in base64 string stored in database? As of now I tried to send email but the email received in plain text.
My flow should be:
Proxy service > Get base64 string from database sequence > Send email sequence.
I tried to find references but none found regarding my issue.
Below are the source code for send email sequence
<?xml version="1.0" encoding="UTF-8"?>
<sequence xmlns="http://ws.apache.org/ns/synapse" name="SendMailSequence">
<log level="full">
<property name="sequence" value="sendMailSequence" />
</log>
<payloadFactory media-type="xml">
<format>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Body>
<ns:binary xmlns:ns="http://ws.apache.org/commons/ns/payload">$1</ns:binary>
</soapenv:Body>
</soapenv:Envelope>
</format>
<args>
<!-- messageBody is from database -->
<arg expression="$ctx:messageBody" />
</args>
</payloadFactory>
<property name="messageType" value="application/octet-stream" scope="axis2" />
<property name="Subject" value="File Received" scope="transport" />
<property name="OUT_ONLY" value="true" />
<send>
<endpoint name="FileEpr">
<address uri="mailto:my-email#gmail.com" />
</endpoint>
</send>
</sequence>

Answer 1

Is there any reason why you have set the messageType as application/octet-stream? If you set the right messageBuilder, it should work right. Have a look at the following links.
http://sachirajapakse.blogspot.com/2016/06/sending-mails-with-attachments-via-wso2.html
Why WSO2 ESB is Encoding Email Attachment in Base64