Known problems with Mail_mime that cause empty lines at some e-mail providers?

Question

I'm sending a PDF and a short text message with Mail_mime 1.8.8 (+ Mail 1.2.0). Almost every test is without a problem. Including GMail and Apple iCloud.

But it seems some recipients have trouble reading the attachment. Users of United Internet (1&1 and GMX) get empty lines between all the lines in the body.

As it's a multipart/mixed e-mail with headers in the body, the attachment is broken.

Is there a known problem with the e-mails generated with Mail_mime that could cause that? Regardless if the e-mail provider is using software that ignores the principles of Jon Postel to be tolerant with the data it receives?

Answer 1

PEAR packages Mail and Mail_mime don't work together without tweaking the parameters to Mail_mime: http://pear.php.net/manual/en/package.mail.mail-mime.mail-mime.php

You need to set EOL to a single linefeed.

Answer 2

check your syntax (Multipart Content-Type, MIME) & structures of header and body:

• Content-Type: multipart : https://www.rfc-editor.org/rfc/rfc2045#page-8
• Representation of Line Breaks : https://www.rfc-editor.org/rfc/rfc2046#section-4.1.1
• 'MIME-Version: 1.0'

as described in RFC822 RFC2045 RFC2046

• MIME Header Fields ................................... 8

• MIME-Version Header Field ............................ 8

  https://www.w3.org/Protocols/rfc822/3_Lexical.html https://www.w3.org/Protocols/rfc1341/7_2_Multipart.html https://www.rfc-editor.org/rfc/rfc822#section-3.2