Setting up Outlook desktop with IMAP and SMTP

Outlook can connect to an ITProMail mailbox over IMAP for incoming mail and SMTP for outgoing mail. Outlook was built around Microsoft accounts and Exchange, so a generic IMAP account works but has fewer features than a native one. Read the limitations section before you decide that Outlook is the client you want for this mailbox.

Before you start

Create an app password in the webmail under Account, then Security. Label it for this computer so you can revoke it independently later. Outlook needs the app password, not your account password.

Adding the account on Windows

In the classic Outlook desktop app, open File, then Add Account. Enter your email address and select Advanced options. Tick the option to let you set up the account manually, then choose IMAP. Enter the values below.

If port 465 is blocked, use smtp.itpromail.com on port 587 with STARTTLS. Outlook may try automatic discovery first and fail with an Exchange-related message. That is expected for this mailbox, so continue with manual setup.

When the account is added, Outlook will download folders and mail. Send a test message to an address you control and check that it reaches the webmail Sent folder.

Adding the account on macOS

The Outlook app for Mac and the new Outlook for Windows have their own account setup flows and may differ in how they handle generic IMAP accounts and app passwords. Use the same server values and app password, and check Microsoft's current documentation for the version you are running.

Limitations to expect

• No native OpenPGP. Outlook does not provide built-in OpenPGP. If you rely on PGP, use a client that supports it, such as Thunderbird, for that mailbox. See PGP in ITProMail.
• Server-side filters are separate. Sieve scripts are managed in the webmail under Account, then Filters. They run on the server regardless of client, but Outlook's own rules run only on the computer where they are defined.
• Exchange features are not available. Shared mailboxes, delegate access and Exchange-based calendar sharing do not apply to this account.
• Feature support changes. Microsoft changes how it supports generic IMAP accounts across Outlook versions. If a setting that worked before stops working, check the current version's documentation before assuming a problem with the mailbox.

Local data

Outlook stores a copy of your mail in local data files on the computer. Those files contain your message content and attachments. Use full-disk encryption on the computer and lock the session when you step away. Removing the account from Outlook does not automatically delete every local copy, so check the data file location if you are retiring the machine.

Revoking access

If the computer is lost or reassigned, revoke the app password for it in the webmail under Account, then Security. The mailbox remains available from other clients.

For the full list of server names, ports and limits, see IMAP and SMTP settings.