# Gmail IMAP/SMTP: why your password keeps getting rejected

> Three steps: turn on 2-Step Verification, create a Google app password, paste it in the dashboard. Send from your own Gmail address, free on every plan.

Source: https://unlimitedmessaging.app/articles/gmail-imap-smtp-app-password

Gmail + IMAP/SMTP

# Connect your Gmail  
_with an app password._

Your own Gmail address, your own mail server, and one app password. Three steps are enough to send email to your customers from the API, the dashboard or your AI assistant, next to WhatsApp, free on every plan.

[Connect my Gmail for free](https://app.unlimitedmessaging.app)[See pricing](https://unlimitedmessaging.app/pricing)

The context

## Your Gmail, your address, your reputation

UnlimitedMessaging does not hand you a sending address: it connects the one you already have. For a Gmail account, that goes through IMAP and SMTP, with a [Google app password](https://support.google.com/accounts/answer/185833) instead of your usual password.

The email channel works like our WhatsApp channel: you bring your own infrastructure. On WhatsApp, you link your own number by scanning a QR code. For email, you connect your own mailbox. Messages leave from your address, through your mail server, so your deliverability and your sender reputation stay yours.

Gmail, like any mailbox, is reached over two standard protocols: IMAP to read incoming mail and SMTP to send. Google does not let IMAP/SMTP clients sign in with your account password: it asks for 2-Step Verification, then an app password made for that one app. That is the one piece you need to create.

This guide walks through the three steps, explains what an app password is for, and covers what happens once your mailbox is connected: sending, inbox, webhooks, bounces. Everything below is free on every plan, the free plan included.

![Illustration: a grid of small icons with one highlighted, with the headline “Connect Gmail with an app password”.](https://unlimitedmessaging.app/_next/image?url=%2Fassets%2Farticles%2Fcovers%2Fgmail-imap-smtp-app-password-en.png&w=3840&q=75)

Definition
App password

A 16-character password that Google generates so an app can sign in to your account, for example an IMAP/SMTP mail client. It is separate from your main password and can be revoked at any time.

Also called a Google app password or application-specific password.

[Source: Sign in with app passwords - Google↗](https://support.google.com/accounts/answer/185833)

Why an app password

## What the app password does for you

It is not an extra hoop: it is how Google lets an IMAP/SMTP client in without ever seeing your real password.

### Google asks for it for IMAP/SMTP

With 2-Step Verification on, a mail client that signs in over IMAP/SMTP cannot type a verification code. Google gives it an app password instead, and that is what UnlimitedMessaging uses to reach your Gmail.

1. 01  
### Your main password stays private  
You never share your Google account password. The app password is a separate credential, created for this one use.
2. 02  
### Revocable at any time  
You can delete the app password from your Google account whenever you want. The connection stops right away, without touching your main password.

Step by step

## Connect Gmail in three steps

A few minutes, from your Google account to the UnlimitedMessaging dashboard.

1. 01  
### Turn on 2-Step Verification  
In your Google account security settings, turn on 2-Step Verification if it is not on yet. App passwords are only available once it is enabled.
2. 02  
### Create an app password  
Go to myaccount.google.com/apppasswords, give the app password a name you will recognize (for example UnlimitedMessaging), and create it. Google shows a 16-character password: copy it.
3. 03  
### Paste it in the dashboard  
In the UnlimitedMessaging dashboard, open the "Connect an email" form, enter your Gmail address and paste the app password. The server settings are detected from your address.

No server settings to type

### IMAP and SMTP settings are detected from your address

For a Gmail address, UnlimitedMessaging fills in imap.gmail.com and smtp.gmail.com on its own. You only provide the address and the app password.

Not on Gmail?

## Your own domain or any IMAP/SMTP provider works the same way

Gmail is just the most common case. The connection relies on standard protocols, not on one provider.

### Your own domain

An address on your company domain connects the same way: address, password, and the server settings are detected from the address.

1. 01  
### Any IMAP/SMTP provider  
If your mailbox offers IMAP and SMTP access, you can connect it. Your emails still leave from your address, through your provider's server.

Not supported yet

### Outlook, Hotmail and Microsoft 365

These mailboxes require an OAuth sign-in rather than an IMAP/SMTP password, so they cannot be connected yet. OAuth support is planned for later.

Once connected

## What changes once your Gmail is connected

Your mailbox becomes a channel, next to your WhatsApp number.

1. 01  
### Emails leave from your own address  
Your customers see your Gmail address, not ours. UnlimitedMessaging is only the transport: the address, the server and the reputation are yours.
2. 02  
### A copy in your Sent folder  
Every email sent through UnlimitedMessaging is copied to the Sent folder of your mailbox, so you find it in Gmail like any other email.
3. 03  
### Incoming emails in the dashboard inbox  
Replies and new emails show up in the dashboard inbox, grouped by thread. When you reply, the thread is kept.
4. 04  
### A message.received webhook  
Each incoming email can also be pushed to your webhook as a message.received event, with its subject, HTML body and attachments. Webhook reception is part of the Medium and Max plans.
5. 05  
### Hard bounces pause the address for 30 days  
When an address hard bounces, it is paused for 30 days for that mailbox, so you do not keep sending to it and hurt your sender reputation.

POST /messageJSON

```
{
  "recipient": "client@example.com",
  "subject": "Your order is ready",
  "text": "Hi, your order is ready for pickup."
}
```

Once Gmail is connected, an email address as recipient plus a subject is all it takes. Add a phone number and the WhatsApp channel to send the same message on both in one request.

Free on every plan

### Your mailbox, your number, one free account

The email channel and multi-channel sending are available on every plan, the free plan included, with no credit card. On the free plan, emails carry a small "Sent with UnlimitedMessaging.app" footer, as WhatsApp messages do. The Medium and Max plans remove it.

FAQ

## Questions about Gmail and app passwords

Google does not accept your account password for IMAP/SMTP sign-ins. It requires 2-Step Verification and an app password, a 16-character code made for one app. UnlimitedMessaging connects over IMAP/SMTP, so it needs one.

At myaccount.google.com/apppasswords, once 2-Step Verification is turned on for your Google account. Google then shows a 16-character password to paste in the "Connect an email" form of the dashboard.

No. The server settings are detected from your email address. For Gmail, you only enter the address and the app password.

Delete the app password from your Google account. It can be revoked at any time, and your main password is never affected.

Not yet. These mailboxes require an OAuth sign-in, which is planned for later. Gmail, your own domain and any IMAP/SMTP provider can be connected today.

Yes. The email channel is available on every plan, the free plan included, with no credit card. Free-plan emails carry a small "Sent with UnlimitedMessaging.app" footer.

Your own Gmail address. Emails go through your own mail server, and a copy lands in your Sent folder. UnlimitedMessaging never provides the sending address.

A common cause is a change of your Google account password: Google then cancels every app password. Create a new one and update it in the dashboard. App passwords are also unavailable for work or school accounts, accounts with Advanced Protection, and 2-Step Verification set up with security keys only.

Sources

## Sources & references

To check the information in this article for yourself:

1. [01Sign in with app passwords↗Google Account Help](https://support.google.com/accounts/answer/185833)
2. [02Turn on 2-Step Verification↗Google Account Help](https://support.google.com/accounts/answer/185839)

![Ilian, senior software engineer](https://ilianazz.com/images/iliazz.png)

Written by

[Ilian](https://unlimitedmessaging.app/authors/ilian) · Senior Software Engineer

A senior software engineer, he founds and runs several tech companies. He builds products around messaging APIs, automation and AI integration, and shares here what he learns while building.

[View LinkedIn profile↗](https://www.linkedin.com/in/ilianAzz/)Updated November 6, 2026

![](https://unlimitedmessaging.app/assets/logos/whatsapp.svg)![](https://unlimitedmessaging.app/assets/logos/email.svg)![](https://unlimitedmessaging.app/assets/logos/sms.svg)

## Connect your Gmail and send from your own address.

Your own mailbox and your own WhatsApp number, in one free account. No credit card.

[Connect my Gmail→](https://app.unlimitedmessaging.app)

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