Covers @outlook.com, @hotmail.com, @live.com, and @msn.com personal Microsoft accounts. Microsoft requires Modern Auth (OAuth2) by default - App Passwords are the supported workaround for any SMTP client that does not implement OAuth, which includes Inflowave's SMTP path.
Step 1 - Enable POP/SMTP access on your mailbox
As of 2024, Microsoft disables POP and IMAP access by default on new Outlook.com accounts. SMTP send via App Password works only after you toggle this on. Most people miss this step and waste an afternoon chasing a 535 auth error that the App Password did not cause.
- Sign in at
outlook.live.com. - Top-right gear icon → View all Outlook settings at the bottom of the panel.
- Left rail, Mail → Sync email.
- Under "POP and IMAP", set Let devices and apps use POP to Yes.
- Click Save.
Step 2 - Enable Two-Step Verification
App Passwords only exist on accounts with 2-Step Verification enabled. Without it, Microsoft hides the entire App Passwords menu - no error, just absence.
- Visit
account.microsoft.com/securityand sign in. - Find Two-step verification and click Set up two-step verification.
- Complete the setup with the Microsoft Authenticator app or a phone number.
Step 3 - Generate the App Password
- From
account.microsoft.com/security, click Advanced security options. - Scroll to the App passwords section.
- Click Create a new app password.
- Microsoft shows a long random password (one-time view). Copy it.
- Paste it into Inflowave immediately. Microsoft will not show it again.
Step 4 - Connect to Inflowave + test send
- Inflowave → Settings → Email → Add sending domain → Custom SMTP.
- Host:
smtp-mail.outlook.com, Port:587. - Username: your full Outlook email.
- Password: the App Password.
- Save, then click Send test on the linked card. A successful 250 confirms SMTP auth + From-address alignment.
- If you get 535 here, go back to Step 1 - the POP setting is the most common cause.
Troubleshooting
Modern Auth is required and you sent the regular password. Use an App Password, not your login password.
POP/SMTP is disabled on the mailbox. Re-run Step 1 - set "Let devices and apps use POP" to Yes.
2-Step Verification is not enabled. Re-run Step 2.
You set the From address to something different from the authenticated mailbox. Send as the same address you used to authenticate, OR add the alias to the account first.
Send limits and account aging
- ~300 messages per day on new Outlook.com accounts. Microsoft does not publish a precise number; this is the observed practical cap.
- The cap expands gradually as the account ages and earns sending reputation - accounts that have been active for 6+ months and consistently send to engaged recipients can sustain higher daily volumes.
- Suitable for transactional and low-volume notification mail. Not suitable for marketing, cold outreach, or any sustained high-volume send.
- Hitting the cap returns
550 5.4.1 Recipient address rejected: Access deniedand outbound is paused for ~24 hours.
