Return receipt is allways sent
Hello, We have recently migrated from Exchange 2013 to Exchange Online. When the setting "Never send return receipt" is set, the return receipt is always sent as soon as the client downloads the mail. If the setting is set to "ask", the return receipt is not sent even if I open the mail. However, if I select the "Ignore" button, the return receipt is sent. All the articles I have found on this issue are 14 years old and refer to Exchange 2007, but in Exchange 2013 it was fine. Only in Exchange Online this behavior started. Outlook does not have this issue. Is there anything I can do about it?
Opaite Mbohovái (2)
When using exchange as a backend, the server admin has access to override your choices to return receipts and usually they do set it to automatically return receipts. So first thing is verify what the online settings for receipts are.
That's the problem. I am the admin ;) The server settings are mostly default. In the meantime, I have enabled "ActiveSyncSuppressReadReceipt" and "ImapSuppressReadReceipt" for the affected mailboxes. This has changed the behaviour slightly, but it's still not as expected: Thunderbird no longer sends a return receipt when the mail is downloaded, but when it is marked as read. Even if the setting to never send a return receipt is enabled.