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POP emails automatically marks read in office365 webpage after been fetched in thunderbird

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I have an office365 email account set up in thunderbird using POP server/ settings : Server name: outlook.office365.com ; Port: 995 ; Encryption method: TLS/SSL

Everything works normal but only one issue. When new emails are retrieved in thunderbird, it automatically marks the email read in office365 webpage.

The new email received in thunderbird still remains unread until I read it but the emails in the webpage of office 365 automatically marks read.

Please is this normal or some kind of bug with thunderbird? or compatibility issue between thunderbird and office365? I thought the emails received with POP leaves emails in the webclient unread

Or are there some settings I can use to prevent this from happening ?

I have an office365 email account set up in thunderbird using POP server/ settings : Server name: outlook.office365.com ; Port: 995 ; Encryption method: TLS/SSL Everything works normal but only one issue. When new emails are retrieved in thunderbird, it automatically marks the email read in office365 webpage. The new email received in thunderbird still remains unread until I read it but the emails in the webpage of office 365 automatically marks read. Please is this normal or some kind of bug with thunderbird? or compatibility issue between thunderbird and office365? I thought the emails received with POP leaves emails in the webclient unread Or are there some settings I can use to prevent this from happening ?

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re :The new email received in thunderbird still remains unread until I read it but the emails in the webpage of office 365 automatically marks read.

Thunderbird has no control over the webmail account with the exception of selecting not to auto delete off server. Pop accounts can only access and download from server Inbox. It is usual for emails to be deleted off server after being popped, but if you have a setting in Account Settings to 'Leave message on server' then it will not be deleted off server. It is not possible for Thunderbird to mark anything as read or not read in the webmail account. However, for a few years there has been many reported cases that Outlook.com automatically mark popped emails as read. POP assumes you have read the emails because they were downloaded regardless of whether you have actually read them or not. These are a couple of examples:

When an email client that uses the POP protocol (such as an email app on a cell phone) fetches new (unread) email from the new outlook.com interface (which runs Exchange servers), the Exchange servers mark that mail (on the server) as being read (even if those email messages were never opened by the user). The old outlook interface's servers did not do this ... the old servers left the fetched mail (on the server) marked as being unread.

The new Outlook Mail interface is not backwards compatible with the old interface. Many customers have complained about this .... both here in Microsoft Community and on the uservoice site .... but so far Microsoft has not done anything to fix it.


Try this: go to the outlook.com webpage, see if there is something under Mail Settings "mark as read" section, you are looing for something like "Don't automatically mark items as read".

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Seçilmiş Həll

re :The new email received in thunderbird still remains unread until I read it but the emails in the webpage of office 365 automatically marks read.

Thunderbird has no control over the webmail account with the exception of selecting not to auto delete off server. Pop accounts can only access and download from server Inbox. It is usual for emails to be deleted off server after being popped, but if you have a setting in Account Settings to 'Leave message on server' then it will not be deleted off server. It is not possible for Thunderbird to mark anything as read or not read in the webmail account. However, for a few years there has been many reported cases that Outlook.com automatically mark popped emails as read. POP assumes you have read the emails because they were downloaded regardless of whether you have actually read them or not. These are a couple of examples:

When an email client that uses the POP protocol (such as an email app on a cell phone) fetches new (unread) email from the new outlook.com interface (which runs Exchange servers), the Exchange servers mark that mail (on the server) as being read (even if those email messages were never opened by the user). The old outlook interface's servers did not do this ... the old servers left the fetched mail (on the server) marked as being unread.

The new Outlook Mail interface is not backwards compatible with the old interface. Many customers have complained about this .... both here in Microsoft Community and on the uservoice site .... but so far Microsoft has not done anything to fix it.


Try this: go to the outlook.com webpage, see if there is something under Mail Settings "mark as read" section, you are looing for something like "Don't automatically mark items as read".