Outlook.com Moving Addresses From Bcc Field to the TO Field When Email is Sent via Desktop Email Client

Ron:

I appreciate the advice.

I have tried using names. I have tried using email addresses. I have tried using Postbox. I have tried using Thunderbird. I even tried creating a new alias account to see if that changed anything - it didn't. When I put an email address in the "To" field, another email address in the "Cc" field and two more email addresses in the "Bcc" field, the result is that the email addresses used in the "To" and "Cc" fields received emails from me and the email addresses used in the "Bcc" field never received my emails when I send from my SMTP server at Outlook.com. If I do the same thing and send the email using an SMTP server at Gmail.com, everything works great and all four emails are received properly.

This problem started about the time my LIVE account was migrated from the web Outlook.com to the new Outlook Mail processes. Apparently most accounts like yours are working fine and a few like mine aren't. I have tried a lot of variations during my tests to pinpoint a particular scenario and nothing I do on my end ever changes the results.

My situation seems to involve something that changed and is not working properly on the backend, and I do not think it is anything you or I will be able to resolve. Someone from MS technical services is needed.

I thank you for your assistance.

Correction:

After further test, it appears that the Office 365 server will not send Bcc emails if you send using an email program.

If you login using a browser, Bcc emails can be sent.

I will test using Windows 10 Mail and Windows Live Mail.

Ron:

THANKS!!

I think you figured out the problem. I hope you agree that all email software, including the MS Office 365 server, should send Bcc emails from a desktop client because Bcc is an integral part of the email process, and I ask you to pass your findings to your MS technical support personnel so they can correct the situation.

Again - thanks and please let me know when this will be fixed.

Ron:

It is now June 23rd. Is MS investigating and trying to resolve these problems, or does MS consider them minor bugs and not working on them?

Here is more insight if it will help anyone.

Problems when using a desktop email client and sending through SMTP server at Outlook.com:

1. When I do not have an email address in the “To” field, do not have an email address in the “Cc” field, do put a single email address or a group list into the Bcc field, and send the email from my “Postbox” email desktop client through my outgoing SMTP server at "Outlook.com", the email goes through "Outlook.com" and "Outlook.com" moves all the email addresses from the “Bcc” field to the “To” field (All my email addresses used to stay in the “Bcc” field as they should until my web account was changed from Outllook.com to Outlook Mail).
2. When I put an email address in the "To" field, another email address in the "Cc" field and two more email addresses in the "Bcc" field, and send the email from my “Postbox” email desktop client through my outgoing SMTP server at "Outlook.com", the result is that the email addresses used in the "To" and "Cc" fields receive emails from me and the email addresses used in the "Bcc" field never receive my emails when I send from my SMTP server at “Outlook.com”.

Notes:

1. My Outlook web page has shown “Outlook Mail” in the top left corner instead of “Outlook.com” for many weeks.
2. I am using incoming imap-mail.outlook.com Port 993 and outgoing smtp-mail.outlook.com Port 587 for my desktop email client server on “Postbox”.
3. I verified all my “Junk” email settings on my Outlook Mail web page.
4. I do not have any “Inbox rules” or “Sweep rules” in my email settings on my Outlook Mail web page.

Testing:

I am reporting a comprehensive set of tests and results using a desktop email client "Postbox", using a desktop email client "Mozilla Thunderbird", a browser mail through “CenturyLink”, a browser mail through “Gmail”, and a browser mail through “Outlook Mail”.

• T1 - Using “Outlook Mail” through the browser to send an email. The fields and results were:
  • From field used a “Live” email account.
  • To field had a “Gmail” email address. The email was received.
  • Cc field had a “Live” email address. The email was received.
  • Bcc field had a “CenturyLink” email address. The email was received.
• T2 - Using “CenturyLink” through the browser to send an email. The fields and results were:
  • From field used a “CenturyLink” email account.
  • To field had a “Live” email address. The email was received.
  • Cc field had a “Gmail” email address. The email was received.
  • Bcc field had a “Yahoo” email address. The email was received.
• T3 - Using “Gmail” through the browser to send an email. The fields and results were:
  • From field used a “Gmail” email account.
  • To field had a “CenturyLink” email address. The email was received.
  • Cc field had a “Yahoo” email address. The email was received.
  • Bcc field had a “Live” email address. The email was received.
• T4 - Using “Postbox” desktop email client to send an email. The fields and results were:
  • From field used a “Live” email account going through the Outlook.com SMTP server.
  • To field had a “Live” email address. The email was received.
  • Cc field had a “Yahoo” email address. The email was received.
  • Bcc field had a “Gmail” email address. The email was NOT received.
• T5 - Using “Postbox” desktop email client to send an email. The fields and results were:
  • From field used a “CenturyLink” email account going through the Centurylink.net SMTP server.
  • To field had a “Live” email address. The email was received.
  • Cc field had a “Yahoo” email address. The email was received.
  • Bcc field had a “Gmail” email address. The email was received.
• T6 - Using “Mozilla Thunderbird” desktop email client to send an email. The fields and results were:
  • From field used a “Live” email account going through the Outlook.com SMTP server.
  • To field had a “Yahoo” email address. The email was received.
  • Bcc field had “CenturyLink”, “Gmail”, and “Live” email addresses. The emails were NOT received.
• T7 - Using “Postbox” desktop email client to send an email. The fields and results were:
  • From field used a “Live” email account going through the Outlook.com SMTP server.
  • To field had no email address.
  • Bcc field had “Gmail” email addresses. The email was received but the address was moved from the Bcc field to the “To” field and the address was visible.

Conclusions:

1. Based on all of the above testing, the problems mentioned above seem to be when there is a combination of using a desktop email client to send an email through the “Outlook.com” SMTP server and putting one or more addresses in the Bcc field as shown in the T4, T6, and T7 tests above. The email address in the Bcc field for T4 and T6 never received the email sent to that address. And, the email address in the Bcc field for T7 was moved to the “To” field and subsequently received.
2. When I checked the source data from the sent messages from T4 and T6, the Bcc information and addresses were all striped away and nonexistent. Apparently something done by the Outlook.com SMTP server processing.
3. When I checked the source data from the sent message from T7, the Bcc information and address was blank and the “To” field contained the address. Apparently something done by the Outlook.com SMTP server processing.