HTML e-mail with attachment problem

[eluser]sophistry[/eluser]
please return with a debug matrix of where your email sending breaks down so you can isolate the problem.

tests (for each service):
send plaintext alone
send html alone
send attachment "alone"
send text and html
send text and attachment
send html and attachment
send all three

also,
RFC 2046 makes for edifying reading see esp section 5.1.3 and 5.1.4 for multipart standards. those section detail the difference between alternative and mixed multiparts - there may be something in changing the default mixed to default to alternative.

finally, it looks like you didn't paste all of the email because there is no closing boundary on the base64 encoded attachment. according to the CI Email.php library code a closing boundary is added.