Proton Mail Bridge is an open-source application that allows you to fully integrate your Proton Mail account with any program that supports IMAP and SMTP. This includes Microsoft Outlook, Mozilla Thunderbird, and Apple Mail.
It runs in the background on your computer and seamlessly encrypts and decrypts your mail as it enters and leaves your computer.
Once you’ve installed and added your account(s) to Proton Mail Bridge, you’ll need to configure your email client. Proton Mail Bridge works with most email clients and applications that support IMAP/SMTP connections.
In this guide, we provide step-by-step instructions to configure the new Outlook app to use Proton Mail Bridge on your Mac. If you have an older version of Outlook installed, take a look at our instructions for Outlook 2019, Outlook 2016, or Outlook 2011.
How to set up the new Outlook for macOS with Proton Mail Bridge
1. Open Outlook, and in the menu bar go to Tools → Accounts.
2. Click Add Email Account.
3. Enter your Proton Mail email address (displayed in the Bridge app under Username) and click Continue.
4. Click Sync directly with IMAP.
5. Click Show Advanced Settings.
6. Enter the details from the Bridge Mailbox details section.
SMTP Outgoing Server and IMAP Incoming Server should be 127.0.0.1.
Note: Don’t use your regular Proton Mail account details. You must use the account details provided in Proton Mail Bridge under Mailbox details.
8. Click Add account, and the account will be added to Outlook.
Now you can use your Proton Mail account with Outlook on your Mac.
With Outlook for macOS, there is no option to add additional addresses (aliases) to the same account so you can send from them. As an alternative, you can switch to split address mode and add each address as a separate account.