Send mail-merge campaigns from Microsoft Outlook through Postfaro

This guide shows how to add your Postfaro sender address to classic Outlook for Windows as a separate, send-only account, and how to send a personalised campaign with Word mail merge.

Your normal mailbox (Microsoft 365, Exchange, Gmail, etc.) stays exactly as it is. You only switch to the Postfaro account when you run a campaign.

Which Outlook? Word’s “Send Email Messages” mail merge works with classic Outlook for Windows (the desktop app included with Microsoft 365 / Office). It does not work with the new Outlook for Windows or Outlook on the web. If you only have the new Outlook, switch back to classic Outlook (there is usually a toggle at the top right of the new Outlook window) [verify UI path], or use another tool from our guides. Outlook for Mac is not covered here.

Before you start

• Your Postfaro setup is Ready in the panel.
• You have created a sender address (for example [email protected]) and copied its SMTP username and password.
• You have your recipient list in Excel (or Outlook contacts), with at least an email column and, ideally, first name and other fields for personalisation. Everyone on it must have agreed to receive your email.

Part 1 — Add the Postfaro sender as a send-only account

Postfaro does not provide an inbox: replies to your sender address are forwarded to the mailbox you chose in the panel. Classic Outlook still asks for an incoming server, so we add the account as POP with a placeholder incoming server, and then tell Outlook never to check it.

The most reliable way to reach all fields is the classic Mail setup dialog: [verify UI path]

1. Close Outlook.
2. Open the Windows Control Panel, search for Mail, and open Mail (Microsoft Outlook).
3. Click Email Accounts… → New…
4. Choose Manual setup or additional server types → Next → POP or IMAP → Next.
5. Fill in:

6. Untick “Automatically test account settings when Next is clicked” (the test would fail on the placeholder incoming server).
7. Click More Settings…:
   • Outgoing Server tab: tick My outgoing server (SMTP) requires authentication and choose Use same settings as my incoming mail server.
   • Advanced tab: set Outgoing server (SMTP) to 587 and Use the following type of encrypted connection to STARTTLS (some versions show “TLS”). Alternatively use 465 with SSL/TLS.
   • Click OK.
8. Click Next, then Finish. If Outlook asks where to deliver new messages, keep your existing data file.

Stop Outlook from checking the placeholder inbox

1. Open Outlook. Press Ctrl+Alt+S (Send/Receive Groups). [verify UI path]
2. Select All Accounts → Edit…
3. In the left list, select the Postfaro account. Keep Include the selected account in this group ticked, keep Send mail items ticked, and untick Receive mail items.
4. Click OK and Close.

Restart Outlook. You should no longer see receive errors for this account.

Send a test

Create a new email, choose the Postfaro address in the From field, and send it to yourself. Check that it arrives and that replying to it reaches the forwarding mailbox you set in the Postfaro panel.

Part 2 — Make the Postfaro account the default (only during the merge)

Word’s mail merge always sends from Outlook’s default account. There is no “From” choice in Word. So, just before the merge:

1. In Outlook: File → Account Settings → Account Settings… → Email tab.
2. Select the Postfaro account and click Set as Default.

You will set your normal account back as default when the merge is finished (Part 4).

Part 3 — Run the mail merge in Word

1. Open your message in Word. Write it as you want it to appear, and include:
   • a short, honest subject in mind (you will type it in step 6);
   • a visible unsubscribe sentence, e.g. “Don’t want these emails? Reply with ‘unsubscribe’ or click here: [link]”;
   • your company name and postal address.
2. Mailings → Start Mail Merge → E-mail Messages.
3. Select Recipients → Use an Existing List… → choose your Excel file and sheet.
4. Optional: Edit Recipient List to remove anyone who should not get this email.
5. Place the cursor where personal details should go and use Insert Merge Field (for example “First_Name”). Use Preview Results to check a few recipients.
6. Finish & Merge → Send Email Messages…:
   • To: the email column of your list;
   • Subject line: your subject;
   • Mail format: HTML;
   • Send records: All.
7. Click OK.

Word passes one message per recipient to Outlook’s Outbox, and Outlook sends them through Postfaro. Keep Outlook open until the Outbox is empty. For large lists this can take a while.

If your list is larger than your remaining daily limit, Postfaro accepts everything and spreads delivery over the following days. You will receive a “Batch queued” email with the expected last send date. See How the daily cap and queue work.

Part 4 — Restore your normal default account

As soon as the Outbox is empty: File → Account Settings → Account Settings… → Email tab → select your normal mailbox → Set as Default.

Messages already handed to Postfaro stay in Postfaro’s queue and are delivered as planned.

Tips

• Sent items: Copies of merged messages are saved in the Sent Items folder of the Postfaro account’s data file. You can delete them after the campaign to save space.
• Attachments: Word’s built-in mail merge cannot add attachments. Link to a file on your website instead — links are also better for deliverability.
• Unsubscribes and bounces: Check Cancelled addresses in the Postfaro panel after each campaign and remove those addresses from your Excel list. Postfaro blocks them anyway, but a clean list keeps your statistics honest.
• Company networks: Some company firewalls block outgoing connections on ports 587/465. If sending fails with a timeout, ask your IT team to allow smtp.postfaro.com on port 587.

Troubleshooting