Email send with PDF as attachment from server is showing as corrupted. Am getting an error File type unknown (application/octet-stream) is not supported.
This is for users with AOL account only. Same email is working fine in clients like gmail, yahoo etc.
AOL began as a proprietary service unconnected to anything else, and its mail program still sometimes behaves accordingly. They devised their own proprietary way of adding attachments to mail messages, and then halfheartedly converted them to and from normal Internet attachment style when dealing with messages entering and leaving their service. This means that attached files will sometimes come through OK, but other times get "munged" in wild and wacky ways. Problems seem to be greater when sending multiple attachments in one message; a single attachment seems to be dealt with correctly, but more than one triggers weird actions such as everything getting shoved into a single ZIP archive file. Anyway, though this shows once again that AOL sucks, it also shows that attachments can cause problems for some recipients that normal plain-text message bodies don't have.
Regardless of the headers() AOL is AOL.
It may not be ideal, but for AOL users you could send them a link to the PDF and provide a brief explanation that their email provider doesn't fully support PDF attachments.
