If your sales team runs on Microsoft Outlook and you're using Apollo.io for prospecting and sequencing, connecting the two is one of the highest-leverage moves you can make. Instead of manually copying email addresses, switching between tabs, and logging activity by hand — Apollo and Outlook work together to automate your outbound, track opens and clicks, and keep your CRM in sync. Here's exactly how to set it up.
Why Connect Outlook to Apollo.io?
The integration between Apollo and Outlook isn't just a convenience feature — it's a performance multiplier. Here's what becomes possible the moment they're connected:
- Send Apollo sequences directly through your Outlook inbox, keeping your sender domain intact
- Track email opens, link clicks, and replies in real time inside Apollo
- Auto-log email activity back to your CRM (HubSpot, Salesforce) without manual data entry
- Use Apollo's Chrome extension to pull contact data directly from Outlook and LinkedIn
- Maintain email deliverability by sending through your own authenticated Outlook account rather than a third-party server
The result is a unified outbound system where Apollo handles the intelligence, targeting, and sequencing — and Outlook handles the actual email delivery, which protects your domain reputation and improves inbox placement.
Set up Apollo.io and connect your Outlook inbox today →
What You Need Before You Start
Before connecting Outlook to Apollo, make sure you have:
- An active Apollo.io account (free or paid)
- A Microsoft 365 or Outlook.com email account with admin access (or permission from your IT admin if on a corporate tenant)
- The Apollo Chrome extension installed (recommended for full functionality)
- Your Outlook account actively used as your primary sending address
If your company uses Microsoft 365 with strict conditional access policies, you may need your IT administrator to whitelist Apollo.io as an approved third-party application before the OAuth connection will succeed.
Step-by-Step: How to Connect Outlook to Apollo.io
Step 1 — Go to Apollo Settings
Log into your Apollo.io account and navigate to:
- Click your profile icon or initials in the bottom-left corner
- Select Settings from the menu
- In the Settings panel, locate Mailboxes or Email & Calendar (depending on your Apollo version, the label may vary slightly)
This is the central hub for all email account connections. Apollo supports Gmail, Google Workspace, Microsoft 365, and Outlook.com from this screen.
Step 2 — Click "Connect Mailbox"
- Click the Connect Mailbox or Add Email Account button
- Apollo will display a list of supported email providers
- Select Microsoft Outlook or Microsoft 365 from the options
Apollo uses OAuth 2.0 authentication for the Outlook connection, which means you don't need to enter your password into Apollo directly. You'll be redirected to Microsoft's own login screen.
Step 3 — Authenticate with Microsoft
- You'll be redirected to Microsoft's authentication page
- Log in with your Outlook or Microsoft 365 email and password
- Microsoft will display a permissions screen showing what Apollo is requesting access to:
- Read and send emails on your behalf
- Access calendar events (for meeting booking features)
- Read basic profile information
- Click Accept to authorize the connection
If your account is managed by a corporate IT administrator and you see an error saying admin approval is required, you'll need to contact your IT team to grant Apollo permission through the Microsoft 365 Admin Center.
Step 4 — Confirm the Connection in Apollo
Once authenticated, you'll be redirected back to Apollo. You should see your Outlook address listed under connected mailboxes with a green active status indicator:
- Verify the email address shown matches the one you want to use for outbound
- Check that the connection status shows Active or Connected
- If it shows an error, disconnect and reconnect, or try clearing browser cookies and repeating the OAuth flow
Step 5 — Configure Your Email Settings
With Outlook connected, Apollo gives you several settings to configure:
- Daily sending limit — Set a cap on how many emails Apollo can send per day through your Outlook account. Start at 50–80/day for new or warmed-up accounts, scaling to 150–200/day for established domains
- Sending schedule — Define the hours and days Apollo can send on your behalf (e.g., Monday–Friday, 8am–5pm in your local timezone)
- Email signature — Import your Outlook signature or create a new one inside Apollo for outbound sequences
- Reply detection — Enable this so Apollo automatically pauses sequences when a prospect replies, preventing awkward follow-up emails after a response
Step 6 — Connect Your Outlook Calendar (Optional but Recommended)
Apollo's meeting booking feature allows prospects to schedule calls directly from a link in your email.
To enable this:
- Under Settings → Meetings, connect your Outlook calendar via the same Microsoft OAuth flow
- Apollo will read your availability and create a booking page showing open time slots
- When a prospect books, the meeting is automatically added to your Outlook calendar and a confirmation email is sent
This eliminates back-and-forth scheduling entirely and works especially well in outbound sequences where you're offering a discovery call as the CTA.
Explore Apollo's full meeting booking and sequencing features →
Installing the Apollo Chrome Extension for Outlook
The Apollo Chrome extension supercharges the Outlook connection by bringing Apollo's intelligence directly into your browser:
- Install the Apollo.io Chrome Extension from the Chrome Web Store
- Once installed, open Outlook in your browser (outlook.office.com or outlook.com)
- The Apollo sidebar will appear, giving you access to contact data, sequencing options, and enrichment without leaving your inbox
- When you open an email from a prospect, Apollo will automatically surface their contact record, company info, and engagement history
This is particularly powerful for inbound lead follow-up — someone emails you, and you can instantly see their full Apollo profile without opening a separate tab.
Troubleshooting Common Outlook Connection Issues
"Admin approval required" error
Your Microsoft 365 tenant has restricted third-party app access. Ask your IT admin to approve Apollo in the Microsoft 365 Admin Center under Enterprise Applications.Connection shows as active but emails aren't sending
Check your daily sending limit — if you've hit your cap, Apollo queues emails for the next sending window. Also verify your Outlook account isn't flagged for suspicious activity by Microsoft.Open tracking not working
Open tracking requires Apollo to insert a tracking pixel into outgoing emails. Some corporate Outlook configurations strip tracking pixels. Check your sequence settings and confirm tracking is enabled at the account level.Signature appearing twice
If your Outlook signature is auto-inserting AND Apollo is adding its own, disable one. Either turn off Outlook's automatic signature for new emails, or remove the signature from Apollo's settings.Key Takeaways
- Apollo connects to Outlook via secure Microsoft OAuth — no password sharing required
- Set your daily sending limits conservatively at first to protect domain reputation
- Connect your Outlook calendar to enable seamless meeting booking inside sequences
- The Apollo Chrome extension brings contact intelligence directly into your Outlook browser inbox
- Corporate Microsoft 365 users may need IT admin approval before the connection can be authorized
Connect your Outlook to Apollo.io and start sending smarter outbound →
FAQ: Connecting Outlook to Apollo.io
Does Apollo work with personal Outlook.com accounts?
Yes. Apollo supports both personal Outlook.com and business Microsoft 365 accounts. The connection process is identical for both.Will emails sent through Apollo show as coming from my Outlook address?
Yes. Because Apollo sends through your connected Outlook mailbox via OAuth, recipients see your actual Outlook email address as the sender — not an Apollo address.Can I connect multiple Outlook accounts to one Apollo account?
Yes. On Team and Organization plans, you can connect multiple mailboxes — useful for agencies managing outbound across multiple client domains or SDR teams with shared sequences.Does connecting Outlook affect my email deliverability?
When configured correctly, it improves deliverability because you're sending through your own authenticated domain rather than a shared sending server. Keep daily limits sensible and warm up new accounts gradually.