ok, i can look further into this one
Here is the fix:
It's actually quite simple as far as I can tell and not related to a PEAR shortcoming.
CRM/Utils/Mail.php near Line 140 (remove the BCC line)
$headers['To'] = self::encodeAddressHeader($toDisplayName, $toEmail);
$headers['Cc'] = $cc;
The Bcc field does not need to be in the header. The recipients list is separately generated including the 'Bcc' addresses, so this header is just used to generate the text for the header of the message,
I'm usually nervous about changes seem too simple, since it usually means I didn't understand something. However I have tested on both SMTP and Sendmail, on Linux Debian Etch server, with Mail.app mail program.
Verified in r18824.
Batch move to verification
verified in rev 23722
Reopening because this bug was never fixed: it is still in 4.6 and 4.7. Full fix coming.
Added links to similar bugs. It has always been difficult to fix since the behavior is different based on which method you are using to send emails: the PEAR library requires different arguments for the Mail_mail mailer as for all other mailers. See code comments in submitted fix.
can u please investigate and submit a patch if needed. Can u also check other email programs