Connect Microsoft 365 or Outlook

Turn on Authenticated SMTP, then Sign in with Microsoft — and what to do when the sign-in stops working.

Updated 1 October 2026

Microsoft 365 and Outlook mailboxes connect with Sign in with Microsoft: you choose the mailbox and allow SalesBullet to send and read its email. We never see the password. On Email accounts, click Add your own and choose Microsoft 365 / Outlook — the page has two steps.

1. Turn on Authenticated SMTP

SalesBullet sends through Authenticated SMTP, which Microsoft switches off in many organizations. An admin turns it on once per mailbox; it can take up to an hour to apply. The page shows how:

  • Bought directly from Microsoft — Microsoft 365 admin center: Users → Active users → the user → Mail → Manage email apps → tick Authenticated SMTP → Save changes. Greyed out? The page says which organization-wide switch blocks it.
  • Bought through GoDaddy — in GoDaddy's Email & Office Dashboard, open the mailbox's settings and turn on SMTP Authentication, or ask GoDaddy's support.

Then click Yes, SMTP is turned on.

2. Sign in with Microsoft

  1. Click Sign in with Microsoft.
  2. Choose the mailbox and allow SalesBullet. The first time, your organization may ask an admin to approve SalesBullet.
  3. Back on Email accounts: "… is connected." It starts at 15 emails per day — see Sending limits and pace.

Connect Microsoft 365 / Outlook: turn on Authenticated SMTP, then Sign in with Microsoft

Note

Automatic warm-up isn't available for Microsoft 365 / Outlook mailboxes yet. You can send campaigns from them as usual.

If it doesn't connect

  • "The sign-in was cancelled, or your organization doesn't allow SalesBullet yet" — a Microsoft 365 admin can approve it.
  • "… is saved, but it can't send yet: … Authenticated SMTP is off for this mailbox" — it's on the list with Error. Once the admin has turned it on, click Check again (↻) on its row, or wait: it's checked again by itself.
  • "… couldn't open the mailbox ("User is authenticated but not connected")" — if it keeps happening, IMAP is off for the mailbox: an admin turns it on under Manage email apps.
  • "… is already connected with a password — remove it first."

When the sign-in stops working

A changed password, removed access or withdrawn consent ends the sign-in. The mailbox shows Disconnected — "The Microsoft sign-in no longer works … — sign in with Microsoft again" — and whoever connected it gets an email. Only you can fix it; it isn't checked again by itself.

  1. On Email accounts, click the mailbox's address.
  2. Click sign in with Microsoft again and sign in to the same mailbox.

It works again, with its limits and campaigns as they were.

A Microsoft 365 account whose sign-in stopped: the reason, and sign in with Microsoft again

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