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Connect your sending mailbox to Eli.

Eli sends from your mailbox, not a shared sender pool, that's how deliverability stays clean and replies land in your own inbox the way your prospects expect. This page walks you through wiring Gmail, Workspace, Microsoft 365, or a custom SMTP host into Eli in about three minutes.

Before you start

Have these details ready

Anything missing here is the most common reason the connect step fails halfway.

A Google Workspace, Microsoft 365, or any IMAP-capable mailbox you control. Personal Gmail works too, paid Workspace deliverability is better.
For Gmail or custom SMTP: two-factor auth on the mailbox, Google requires it before it'll let you generate an app password. Outlook / Microsoft 365 skips this entirely, it connects with one-click Sign in with Microsoft.
For Gmail/SMTP, permission to generate an app password on the account, or admin-level access if your Workspace blocks app passwords by policy. Outlook needs no app password.
Optional: any alias or alternate address you want recipients to see. It must already be attached to the primary mailbox or verified as a send-as identity; it will not have its own SMTP or IMAP login.

Walkthrough

Pick your provider

Eli supports four kinds of mailboxes. Pick the one that matches the account you're going to send from, the rest of the steps branch off this choice.

Gmail

Personal @gmail.com address. Needs an app password, 2FA must be on.

Google Workspace

Custom domain on Google. Same app-password flow as Gmail. If your admin disabled app passwords, ask them to flip the policy or use a service account.

Microsoft 365 / Outlook

Office 365 or @outlook.com. One click, Sign in with Microsoft. No password or app password, Microsoft disabled those for Outlook mail. Skip step 2.

Custom SMTP / IMAP

Anything else, FastMail, ProtonMail Bridge, Zoho, your own mail server. You'll fill the host and port by hand.

Generate an app password

This is where most setups stall. Eli does not log in with your regular password, that path is blocked by Google and Microsoft for third-party SMTP. You need a 16-character app password generated from your account's security panel.

Google / Workspace

Open myaccount.google.com while signed into the mailbox you want to connect.
Go to Security, then turn on 2-Step Verification if it isn't already.
Search the page for App passwords (sometimes hidden under "How you sign in to Google"). Open it.
Name the password Ciela and click Generate. Copy the 16-character string, spaces don't matter, paste it into Eli in step 4.

Microsoft 365 / Outlook

Nothing to do here, skip straight to step 3. Microsoft turned off passwords and app passwords for Outlook and Microsoft 365 mail, so there's no password to generate. You'll connect with a one-click Sign in with Microsoft in the connect modal instead, which is more secure and keeps reply detection working.

Custom SMTP hosts skip this step, your mail provider's panel will either give you the regular password or its own equivalent.

Open the connect modal

Head to /dashboard/settings, click the Connections tab, scroll to the Email mailboxes card, and open Eli to connect the mailbox. The modal there is where you'll paste the app password from step 2.

If you're still in onboarding, the same modal opens from the "Connect mailbox" card on Step 4 of the wizard. Same fields, same test pass.

Fill the fields

The modal asks for seven things. Follow these golden rules to pass the test on your first try:

Outlook / Microsoft 365: this whole step doesn't apply, you connect with one-click Sign in with Microsoft, no fields to fill.
Do not use your regular password for Gmail or custom SMTP; only use a 16-character App Password.
For Gmail, the From Email and SMTP Username are usually identical unless you are sending from a verified alias.
If you are sending from an alias, keep the alias in From Email and authenticate with the primary mailbox in SMTP Username.
Make sure there are no accidental spaces at the start or end of your paste.

ProviderGoogle Workspace
Gmail, Workspace, Microsoft, or Custom SMTP. Picking this autofills the server details for you.
Account namePrimary Work Email
An internal nickname for this mailbox. Only you see this in the settings list and campaign picker.
From nameYour Name
What recipients see in the 'From' line of their inbox. Use your real name, not a brand name, for better deliverability.
From emailalias@example.com
The public-facing address recipients see. Use the primary mailbox address, or a verified alias/send-as address that belongs to that mailbox.
SMTP usernameprimary@example.com
The real mailbox Eli uses to authenticate against the mail server. For aliases, this stays the primary account, not the alternate address.
App passwordgenerated app password
The 16-character string from step 2, generated for the primary mailbox. Eli uses this instead of your regular password to stay secure.
Daily limit50
How many emails Eli can send from this mailbox per day. New mailboxes should start low (around 50) to build reputation.

Test connection

Hit Test and save. The modal opens an SMTP and IMAP handshake against your host, a wrong password fails fast (under two seconds) so you don't sit there wondering. If it passes, the account saves and the modal closes itself.

For aliases, the test still authenticates the primary mailbox. Receiving also happens through that primary inbox; the alias only changes the visible sender or reply address after your provider is configured to route it there.

If it fails, the error code is the thing to read first, scroll down to the Common errors section below for what each one means.

Verify in settings

Back on /dashboard/settings, the new account appears under Email mailboxes with a champagne dot and the status pill reading active. The daily counter shows 0/50 on day one, Eli ramps that up automatically as the mailbox warms.

If the dot is red and the row says "Disconnected, reconnect to resume sending," the password was rejected after save, head back to step 2 and regenerate.

Aliases

Alternate addresses are not separate logins

Use the alias as the sender identity, not as the SMTP or IMAP username.

An email alias can receive mail and, once verified, appear in the From line. It is not a mailbox with its own password. If you try to connect Eli with an alias as the SMTP Username, the provider will usually reject the login with auth_failed, 535, or 550.

Authenticate with the primary mailbox, for example primary@example.com, plus that mailbox's app password or OAuth connection.
Put the alias, for example alias@example.com, in From Email only after the provider has verified it as a send-as address.
For Google Workspace, add the alias to the user in Admin, then in Gmail go to Settings > See all settings > Accounts > Send mail as and add the alternate address with Treat as an alias checked.
Replies to the alias should route back into the primary inbox, so Eli's IMAP reply detection should stay connected to that primary mailbox too.

Common errors

When the test fails, read this first

Five failure modes cover ninety-percent of rejected connections.

App password rejected
By far the most common one. Either the password was typed wrong, or Google rotated it because the mailbox's 2FA was reset, or your Workspace admin disabled app passwords by policy. Regenerate the password (step 2) and paste it again. If your admin blocked app passwords, ask them to allow them for your account or move to a service account.
auth_failed
Same family as above, the host accepted the connection but rejected the credentials. Almost always a wrong password, an alias used as the SMTP username, or a sender email that doesn't match the mailbox the password belongs to.
Alias used as SMTP username
Aliases and alternate addresses do not have their own SMTP or IMAP credentials. Authenticate with the primary mailbox, then use the alias only as the From Email after it has been configured as a verified send-as address.
Connection timeout / host_unreachable
The host or port is wrong. For custom SMTP, double-check both against your provider's docs, port 587 with STARTTLS or 465 with SSL are the usual answers. For Gmail and Microsoft, click your provider in the dropdown again to re-autofill.
TLS handshake failed
Your host doesn't support the encryption mode Eli tried. Toggle the SSL checkbox to the opposite state and re-test, that flips between STARTTLS on 587 and implicit TLS on 465.
Mailbox not found / 550
The sender email you entered doesn't exist on that host, or it's an alias the host won't authenticate. Use the literal primary address of the mailbox the app password was generated for as the SMTP username, and only use the alias as From Email after send-as is configured.

What happens next

Once Eli has a connected mailbox, he'll start drafting emails the moment you create an Email campaign or an Omnichannel flow that includes an email step. Drafts queue up against the mailbox you connected, daily volume ramps automatically (50 on day one, climbing as the mailbox warms), and replies land in your own inbox so you can handle the human conversations the way you always have. Eli watches for bounces and auth errors and pauses sending if the mailbox flips to disconnected, you'll see the red dot in settings if that happens.

Every email Eli sends is signed off for you automatically. By default the signoff is your account's display name plus your company, so it always matches the From line. With Ciela AI and Agency you can shape the rest of it, a title, links, a logo, and a social row, in the Signature tab in account settings, with a live preview. Keep it light: for cold email a plain signature reads more human and lands better than a heavy one.

Need help?

Ciela can walk you through any step. Or write to support@ciela.ai. You can also reach out to Adhiraj directly on LinkedIn — feel free to attach your issue in a connection note or InMail.

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