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Master Inbox: setting it up, reading replies in an email app, and who your reply is sent as

How to create a Master Inbox, attach mailboxes, connect it (or any mailbox) to BlueMail or Outlook over IMAP (Gmail isn't supported), which address your reply goes out from, and what to check if it won't connect.

Your Master Inbox brings replies from your SMTP mailboxes into one place. Maildoso has no built-in email viewer or webmail — to read replies, you connect the Master Inbox (or an individual mailbox) to a regular email app over IMAP. 📹 Video walkthrough: how to set up and use the Master Inbox.

Setting it up

  1. Open Master Inbox in the left menu and click Create Master Inbox. Enter the address you want — it must be on the maildoso.email domain. The password is generated automatically.

  2. Attach mailboxes to it: on the Email accounts page, select your SMTP mailboxes and choose Bulk actions → Change forwarding for Maildoso, then pick the Master Inbox address. The Attached mailboxes column on the Master Inbox page shows how many mailboxes forward to it.

  3. Get the login details: click the arrow at the end of the Master Inbox row. It shows the user name, IMAP host (imap.apollo.maildoso.com), IMAP port (993), password, SMTP host (smtp.maildoso.com) and SMTP port (587). The page lists your addresses and settings only — it doesn't display the emails themselves.

  4. Recommended: click Set Up WarmUp filters and activate the filter for your warmup tool so warmup traffic is hidden and you only see real replies — see Warmup Filters. Filters only work for @maildoso.email Master Inbox addresses.

Automated responses (such as out-of-office replies) and verification codes (OTPs) are not forwarded to the Master Inbox for security reasons — to see them, open the individual mailbox in your email app. This page doesn't cover Google Workspace mailboxes, which don't use the Master Inbox — see Forwarding Addresses / Master Inbox.

Connecting the Master Inbox (or any mailbox) to an email app

  • Supported email apps: BlueMail and Outlook. We recommend BlueMail for the Master Inbox — the Master Inbox page links to a guide (How to setup BlueMail). Manyreach is also compatible with Maildoso IMAP/SMTP mailboxes.

  • Gmail / Google can't be used — including Gmail's "Check mail from other accounts" and "Send mail as" settings and the Gmail mobile app. If you want replies in a personal Gmail inbox, see Can I forward my replies to my personal Gmail or Outlook?

  • BlueMail setup: Add account → Manual setup (not the quick-setup box) → IMAP → enter the email + password.

  • Incoming (IMAP): port 993, SSL/TLS. For a @maildoso.email Master Inbox the host is always imap.apollo.maildoso.com (including any extra Master Inbox created via the API). For an individual mailbox, copy the IMAP host from your exported CSV — hosts differ between mailboxes.

  • Outgoing (SMTP): smtp.maildoso.com, port 587, STARTTLS — the same for every mailbox on every account.

  • Attachments sent to Maildoso mailboxes are received normally; sending attachments isn't supported — see Can I send attachments from Maildoso mailboxes?

Expect to see more replies here than in your sequencer

Your Master Inbox receives every reply to every attached mailbox directly over IMAP, so new messages appear immediately. Sequencers such as Instantly sync separately and don't always pick up every reply — it's normal to see noticeably more replies in the Master Inbox (often around 30% more) than your sequencer reports. If a reply is in the Master Inbox but not in your sequencer, nothing was lost on our side.

Who your reply is sent as

  • A prospect replies to an email you sent: Reply or Reply all from the Master Inbox always goes out as your original mailbox, never as the Master Inbox.

  • A prospect wrote to your mailbox first: plain Reply goes out from the Master Inbox address; Reply all (or adding the mailbox as a second recipient) sends it as that mailbox.

  • You start a new message: put the destination email and the Maildoso mailbox connected to that Master Inbox in the To: field — it goes out from that mailbox.

  • You reply to a message originally sent from the Master Inbox: the reply goes out from the Master Inbox address.

In short: whenever a specific mailbox is identifiable as the recipient or is cc'd, replies go out as that mailbox.

If you can't connect in your email app

  • Make sure you're using BlueMail or Outlook — Gmail won't connect, whatever settings you use.

  • Check for stray spaces in the email, password, host or port fields — a common cause of failed connections.

  • Re-export the credentials (Email accounts → select the mailbox → Export accounts → Download selected accounts as CSV) rather than relying on details copied earlier.

  • Use IMAP (not POP), the full email address as the username, and the exact host/port/encryption above.

  • 535 authentication errors usually mean the domain isn't Active yet, its nameservers were changed or have expired, or it was transferred out of Maildoso (IMAP may still log in while SMTP relay is disabled). Once the domain is Active again, download a fresh CSV and reconnect.

  • Still stuck? Contact us — if you're unsure which IMAP host a mailbox uses, we'll confirm it.

If a reply seems missing, see Not getting emails forwarded to the Master Inbox.

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