Before you can run your first outreach campaign or start warming up a mailbox in OutreachFlow, you need to connect a sending email account. This guide walks you through connecting any email provider — including Gmail — using the Custom SMTP/IMAP method.
What Is SMTP/IMAP and Why Does It Matter?
When OutreachFlow sends an email on your behalf, it uses SMTP (Simple Mail Transfer Protocol) — the same protocol your email client uses to send messages. When it reads replies and incoming emails, it uses IMAP (Internet Message Access Protocol).
By connecting your mailbox via SMTP and IMAP, OutreachFlow can:
- Send outreach emails directly from your address (your actual domain, your actual inbox)
- Read replies so the AI can continue the negotiation automatically
- Track bounces and auto-pause your account if delivery problems arise
This means your emails land in recipients’ inboxes looking exactly like they came from you — because they did.
Before You Start
You will need the following from your email provider. Most providers publish these in their help center under “SMTP settings” or “manual email setup”:
- SMTP host (e.g.
smtp.yourdomain.com) - SMTP port (typically
587for TLS or465for SSL) - SMTP encryption (TLS, SSL, or none — use TLS or SSL whenever available)
- SMTP username (usually your full email address)
- SMTP password (your email account password, or an app-specific password)
- IMAP host (e.g.
imap.yourdomain.com) - IMAP port (typically
993for SSL or143for TLS) - IMAP encryption (SSL recommended)
- Reply-to / From address (the email address you want to send from)
If your IMAP credentials are the same as your SMTP credentials (they usually are), you only need to enter them once.
Step-by-Step: Connecting Your Email Account
Step 1. Go to Email Accounts
Log in to OutreachFlow and navigate to Email Accounts in the left sidebar. This is where all your connected mailboxes live.
Step 2. Click “Add Account”
In the top-right corner of the Email Accounts page, click the Add Account button. You will see a form to enter your email credentials.
Step 3. Choose “Custom SMTP/IMAP”
Select the Custom SMTP/IMAP option. This works with virtually any email provider: Google Workspace, Microsoft 365, Zoho Mail, Mailgun SMTP relay, privately hosted mail servers, and more.
Step 4. Fill In Your SMTP Settings
Enter your SMTP details:
| Field | What to enter |
|---|---|
| SMTP Host | Your provider’s outgoing mail server (e.g. smtp.gmail.com) |
| SMTP Port | 587 (TLS) or 465 (SSL) |
| Encryption | TLS or SSL (never “none” for a live sending account) |
| Username | Your full email address |
| Password | Your email password or app-specific password |
Step 5. Fill In Your IMAP Settings
Enter your IMAP details. If they are the same as your SMTP credentials, most fields will pre-fill automatically:
| Field | What to enter |
|---|---|
| IMAP Host | Your provider’s incoming mail server (e.g. imap.gmail.com) |
| IMAP Port | 993 (SSL) |
| Encryption | SSL |
| Username | Your full email address |
| Password | Same as SMTP password |
Step 6. Set Your Reply-To Address
Enter the From / Reply-To email address — the address that will appear in the “From” field when recipients receive your emails. This is typically the same email address you are connecting.
Step 7. Test the Connection
Click Test Connection. OutreachFlow will attempt a real login over both SMTP and IMAP and report back immediately. If the test fails, the error message will tell you exactly what went wrong (wrong password, wrong port, TLS mismatch, etc.).
Fix any errors the test surfaces and re-run the test until it passes. Do not skip this step — a failed test means campaigns won’t send.
Step 8. Save
Once the test passes, click Save. Your account status will show as Connected and sending status as Active. You are ready to use this mailbox in campaigns and warmup.
Connecting Gmail via Custom SMTP/IMAP
Gmail has some extra security layers, so the process has one additional step: generating an App Password. This is a 16-character password that Google generates specifically for third-party apps like OutreachFlow, so you never have to give it your real Google account password.
This method works for both personal Gmail accounts (
@gmail.com) and Google Workspace accounts (@yourcompany.com).
Step 1. Enable 2-Step Verification on Your Google Account
App Passwords require 2-Step Verification (2FA) to be turned on. If you haven’t done this yet:
- Go to myaccount.google.com/security
- Under How you sign in to Google, click 2-Step Verification
- Follow the prompts to enable it
Step 2. Generate an App Password
- Go to myaccount.google.com/apppasswords (you may be prompted to sign in again)
- Under Select app, choose Mail (or type a custom name like “OutreachFlow”)
- Under Select device, choose Other (custom name) and type “OutreachFlow”
- Click Generate
- Google will display a 16-character password. Copy it — you won’t see it again
If you don’t see the App Passwords option, make sure 2-Step Verification is fully enabled and that your account is not managed by an organisation that has disabled App Passwords.
Step 3. Connect in OutreachFlow Using These Settings
Go back to OutreachFlow → Email Accounts → Add Account → Custom SMTP/IMAP, and enter the following:
SMTP Settings:
| Field | Value |
|---|---|
| SMTP Host | smtp.gmail.com |
| SMTP Port | 587 |
| Encryption | TLS |
| Username | Your full Gmail address (e.g. you@gmail.com) |
| Password | The 16-character App Password you just generated |
IMAP Settings:
| Field | Value |
|---|---|
| IMAP Host | imap.gmail.com |
| IMAP Port | 993 |
| Encryption | SSL |
| Username | Your full Gmail address |
| Password | The same 16-character App Password |
Reply-To address: Your full Gmail address.
Step 4. Test and Save
Click Test Connection. If everything is correct, both SMTP and IMAP will connect successfully. Click Save and you are done.
Tips for a Healthy Sending Account
Use a dedicated sending mailbox. Avoid connecting your primary inbox that you use for day-to-day email. Instead, set up a secondary address on your domain (e.g. outreach@yourdomain.com) to protect your main deliverability reputation.
Set sensible sending limits. After saving your account, go to the Account Info tab and review your daily and hourly sending limits. OutreachFlow will never exceed these — it is better to start conservative and increase over time.
Enable warmup before launching campaigns. If the mailbox is new or has been inactive, use OutreachFlow’s warmup system first. Warmup gradually increases your sending volume to build a positive sender reputation before you hit prospects with campaign emails.
Watch for auto-pause notifications. If OutreachFlow detects a spike in bounces or other delivery problems, it will automatically pause the account and notify you. When this happens, check your SMTP credentials are still valid (passwords expire, App Passwords can be revoked) and investigate the bounce reason before resuming.
Troubleshooting
“Authentication failed” error during the test Your username or password is incorrect. For Gmail, make sure you are using the App Password, not your regular Google account password.
“Connection timed out” or “Could not connect to host” The SMTP or IMAP host or port is wrong. Double-check your provider’s documentation. Some providers block port 587 and require 465 instead (or vice versa).
“TLS negotiation failed” Try switching the encryption setting between TLS and SSL, or check if your provider requires a specific TLS version.
“Less secure app access” error on Gmail This error no longer appears for accounts using App Passwords. If you see it, you may be entering your regular password instead of the App Password. Generate a new App Password and try again.
The account connects but emails aren’t sending Check the Sending Status field on your account. If it shows “Paused”, there will be a reason code and message explaining why. Resume the account once the underlying issue is resolved.
What’s Next?
Now that your email account is connected, you are ready to:
- Start a warmup to build your sender reputation before cold outreach
- Create your first campaign and let OutreachFlow handle the full negotiation from first touch to deal won
If you have any questions or run into an issue not covered here, reach out to our support team and we will get you sorted.
OutreachFlow — automated guest-post outreach, from discovery to deal.