PHP sent emails have =0A=0A instead of new lines -

For some time now some of my users have encountered problem I = 0 A = 0a I send them via PHP I am Mail-behavior works well through email client, but PHP generated emails always appear with some users (a minority). Googling finds a good result, all search results seem to be associated with some approach - and it seems that all approaches users will suffer from this problem is unacceptable. Does anyone know the correct way to deal with it properly and avoid these new line encoding issues?

EDIT: FYI I am using Zend's Mailer class.

Thanks

Edit 2:

Changing the encoding type did not work. I have encoded the headers in base 64, and the body has got distorted material up to 64. Then I tried with the base 64 header and did the base 64_deckode ($ body) on the body, and it was okay on the user's "CNR server, but not in the inbox" which means it too. When I tried to mb_convert_encoding base64, I got an encoded string instead of body, so there was no benefit.

What else can I try? The Zend Mailer only supports quotationable print and base 64 header encoding. It is not certain what to do with body to match the quoted printable encoding ...

< P> The email body is encoded - but the declaration in the email is mime type text / html (or text / plain or undefined).

How do you make the body of the email encoding, depends on you.