Connecting mailboxes

Astreo is a client, not a provider. Connect your existing mailboxes via OAuth or IMAP.

Astreo connects existing mailboxes. Preferably via OAuth (Microsoft 365/Outlook) - more secure and with no password in Astreo - or via IMAP/SMTP for any other provider. You can run as many accounts in parallel as you like.

Connect Gmail (OAuth) - currently unavailable

Note: The Gmail connection is currently unavailable. Astreo does not request any Gmail permissions at this time; Google's approval for Gmail access is still pending. Until then, please connect a Google mailbox via IMAP/SMTP using an app password. Once available, it will work like this:

• Open account settings → Connect mailbox → Google.
• You're redirected to Google and confirm access to email.
• Back in Astreo the account is ready immediately; the first sync starts automatically.

Astreo then only stores an encrypted access token, never a password.

Connect Microsoft (OAuth)

• Account settings → Connect mailbox → Microsoft.
• Sign in and consent in your Microsoft / Microsoft 365 account, then return to Astreo.
• Works for Outlook.com and business Microsoft 365 mailboxes.
• If Microsoft shows "Need admin approval", your company doesn't let you consent yourself. Astreo then shows a link you pass on to your IT.

Microsoft requires approval by your IT

Many companies don't let employees give apps access to their mailbox themselves. Microsoft then shows "Need admin approval" – a page where you can't get any further. Astreo helps in three places:

• Before connecting, the “Connect mailbox” dialog points out this message and says what to do.
• If you come back without a result – via the link on the Microsoft page, with “Back” in your browser or by opening Astreo again –, Astreo shows the dialog “Your IT needs to approve Astreo” with a ready-made link for your IT to copy.
• When signing in with Microsoft, the sign-in page explains the same and links to the instructions. Until Astreo is approved, sign in with your password or a login link.

Why this happens, what your IT has to do and which permissions Astreo requests is described on a separate page: Approve Astreo in Microsoft 365.

Connect IMAP/SMTP

For providers without OAuth (or your own mail servers):

• IMAP (receiving): host, port and whether TLS/SSL.
• SMTP (sending): host, port, encryption.
• Credentials: username and password - stored encrypted at rest, never logged in plaintext.

Many providers require an app password instead of your normal password - check their security settings.

Multiple accounts & account colours

Connect as many mailboxes as you need. In the left column, "All mailboxes" bundles the shared inbox; each account also appears individually below. You can assign each account a colour - so in the combined list you can tell at a glance which address a mail went to.

Synchronisation & status

• Astreo syncs incrementally in the background; new mail appears automatically.
• Use "Fetch now" to trigger an immediate sync.
• Per account you see the last sync time and any sync errors (e.g. expired credentials). For OAuth accounts, re-authorising is then enough.