manage default folders in Thunderbird

user-guide/thunderbird_for_o365.md

@@ -45,21 +45,48 @@ Here please enter first the full name (as it should be shown in outgoing emails)
 
 ![Incoming Server Options](thunderbird_for_o365/thunderbird06_incoming_server_entry.png)
 
-For "INCOMING SERVER" set the "Hostname" to `outlook.office365.com`, the "Port" to `993`and select `SSL/TLS` in the "Connection security" dropdown if that does not happen automatically. For "Authentication method" select `OAuth2`.
+For "INCOMING SERVER" set the "Hostname" to `outlook.office365.com`, the "Port" to `993` and select `SSL/TLS` in the "Connection security" dropdown if that does not happen automatically. For "Authentication method" select `OAuth2`.
 
 ![Outgoing Server Options](thunderbird_for_o365/thunderbird07_outgoing_server_entry.png)
 
-For "OUTGOING SERVER" set the "Hostname" to `smtp.office365.com`, the "Port" to `587`and select `STARTTLS` in the "Connection security" dropdown. For "Authentication method" select `OAuth2` and then finish by clicking on "Done".
+For "OUTGOING SERVER" set the "Hostname" to `smtp.office365.com`, the "Port" to `587` and select `STARTTLS` in the "Connection security" dropdown. For "Authentication method" select `OAuth2` and then finish by clicking on "Done".
 
 ![OAuth2 Login](thunderbird_for_o365/thunderbird08_oauth_login.png)
 
-This is followed by a Microsoft Login page where you need to enter your normal PSI AD/Windows password, maybe asking for second factor authentification (Authenticator app or token code).
+This is followed by a Microsoft login page where you need to enter your normal PSI AD/Windows password, maybe asking for second factor authentification (Authenticator app or token code).
 
 ![Done](thunderbird_for_o365/thunderbird09_success.png)
 
-With successful authentication you then close the "Account Setup" tab and enjoy the inbox or use one of the direct links for further configuration tuning, for some of them see the next two chapters
+With successful authentication you then close the "Account Setup" tab and enjoy the inbox or use one of the direct links for further configuration tuning, for some of them see the next two chapters.
 
+## Use O365 Default Folders
 
+Thunderbird and O365 use by default different folders for sent and deleted messages. Following guide needs only to be followed once, after Thunderbird has marked the folders on the server and other Thunderbird instances connecting to it will automatically use the correct folder. Note you then still need to do the last step to not get two copies of the same sent message in the "Sent Items" folder.
 
+![Open Account Settings](thunderbird_for_o365/thunderbird10_account_settings.png)
 
+Via the hamburger menu at the top right open the "Account Settings" window.
 
+### Folder for Deleted Messages
+
+![Account Settings for Deleted Messages](thunderbird_for_o365/thunderbird11_deleted_folder.png)
+
+Then select for your account "Server Settings" and there select the "Deleted Items" entry in the dropdown menu "When I delete a message: Move it to this folder:".
+
+### Folder for Sent Messages
+
+![Account Settings for Sent Messages](thunderbird_for_o365/thunderbird12_sent_folder.png)
+
+The folder for the sent messages need also to be corrected. Go to "Copies & Folders" of your account and there select for "When sending messages, automatically: Place a copy in:" the "Other:" option and in the dropdown menu after the folder "Sent Items" of your account.
+
+Then send a test mail and check how many pop up in this folder:
+
+![Two Sent Messages](thunderbird_for_o365/thunderbird13_two_sent_messages.png)
+
+It looks like O365 does this already automatically, so this can be disabled in Thunderbird by opening up again the Account Settings.
+
+![No Sent Messages Copy](thunderbird_for_o365/thunderbird14_no_copy_of_sent_messages.png)
+
+Go to "Copies & Folders" of your account and untick below "When sending messages, automatically:" the "Place a copy in:" option.
+
+Note I still would not shortcut the first selection the "Sent Item" folder here so it gets properly marked as such by Thunderbird first.