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+# Configure Thunderbird for 0ffice365
+
+## Account and MFA ready?
+Before connecting to Thunderbird to Office365, you need to have your MFA token/app configured.
+
+If you use an app or SMS, then you can set it up directly at [Microsoft](https://aka.ms/mfasetup). Note that when you select the app and use "Use verification code", then you can also use 3rd party OTP apps.
+
+For all the options check out the internal [knowledge base article](https://psi.service-now.com/kb_view.do?sysparm_article=KB0002928)
+
+## Software Installed?
+
+The package `thunderbird` needs to be installed before starting.
+
+## Import PSI TLS Interception CA Certificate
+
+Inside the PSI network access to E-Mail services using IMAP is protected by automatic malware scanning.
+
+You get the [certificate in a zip file](https://drive.switch.ch/index.php/s/VK5zE9c0RRKIH8i/download) and unpack it.
+
+Open Thunderbird. If this is your first account, it will show a account setup assisant which you can exit or close.
+
+![Open Settings](thunderbird_for_o365/thunderbird01_open_settings.png)
+
+Then open the hamburger menu at the top left and select "Settings".
+
+![Search for Certificate Settings](thunderbird_for_o365/thunderbird02_certificate_settings.png)
+
+There type `certificate` into the search box at the top left. Then press below the "Manage Certificates..." button.
+
+![Search for Certificate Settings](thunderbird_for_o365/thunderbird03_certificate_import.png)
+
+Here click on "Import..." and then select the previously downloaded and unpacked file "cert_PSI_FW_SSL_Scanner_TRUST.crt".
+
+![Trust Certificate](thunderbird_for_o365/thunderbird04_trust_certificate.png)
+
+Now tick the checkbox "Trust this CA to identify websites" and confirm this and the previous dialog with "OK". Finally close the "Settings" tab.
+
+## Configure Your Mail Account
+
+To add a new account open the hamburger menu on the top left. There choose "New" -> "Existing Mail Account...".
+
+![Set Up Your Existing Email Address](thunderbird_for_o365/thunderbird05_address_entry.png)
+
+Here please enter first the full name (as it should be shown in outgoing emails) and your email address. As no password is used yet remove the "Remember password" tick and go on by clicking the small "Configure manually" link, which opens more options below:
+
+![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`.
+
+![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".
+
+![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).
+
+![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
+
+
+
+
+
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