1723074 - sending email to my own Hotmail address is rejected as SPAM (by Microsoft)

Status: RESOLVED DUPLICATE of bug 1722916

(Thunderbird :: Untriaged, defect)

Description

[Julie Andrews]

Attachment: Returned email response from Microsoft Servers.

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36

Steps to reproduce:

Since release of Thunderbird 78.12.0 (possibly earlier - first noticed 15 July 2021):
Address email to my own Hotmail account in the To: box
(Optional: include range of other email addresses in the BCC field)
Enter "test" in the subject line - or any other text
Enter "test" in the body of the email - or any other content
Send email

Actual results:

Email immediately rejected by Microsoft Outlook servers as spam - delivery to recipient address not attempted. Completely reproducible every time.
(Optional: when other addresses included on BCC line: all are immediately rejected by Microsoft Outlook servers as spam - delivery to recipient addresses not attempted.) Error report is '550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)'
Reported to Microsoft Support [Case #:1025517216] who diagnose that this is a Thunderbird problem.

Expected results:

Email should be delivered to myself.
N.B. Emails to any other email address can be sent successfully via Thunderbird. Email from any other address can be received successfully via Thunderbird.
Email to my Hotmail account using Microsoft Email Client can be sent and received successfully.
Email to my Hotmail account via Outlook.Com website can be sent and received successfully.

Comment 1

[Alfred Peters [:infofrommozilla]]

(In reply to Julie Andrews from comment #0)

Created attachment 9233911 [details]
Returned email response from Microsoft Servers.

Steps to reproduce:

Since release of Thunderbird 78.12.0 (possibly earlier - first noticed 15 July 2021):

This will not have been caused by a change in TB but in Outlook.

Address email to my own Hotmail account in the To: box

I have no Hotmail account.

Actual results:

Email immediately rejected by Microsoft Outlook servers as spam - delivery to recipient address not attempted. Completely reproducible every time.

Outlook or Hotmail?
For my Outlook account I can confirm that the Outlook server rejects the mail as SPAM if addressed to my own email address. Sending the same message to a different address works fine.

Error report is '550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)'

Exactly.

Reported to Microsoft Support [Case #:1025517216] who diagnose that this is a Thunderbird problem.

Sorry, but that's non -ahem- believable.
It is up to them to name the SPAM criteria. How are we supposed to know what they are looking for. I think the support doesn't know themselves.

I guess it is because of the FROM=TO. But we can hardly change anything in the TB.

Comment 2

[Alfred Peters [:infofrommozilla]]

This is likely to be the same story as in bug 1722916