Cassie’s Inbox Manager Automation takes over repetitive inbox management tasks, so you can focus on what really matters — your customers and your business.
Here’s what it does:
Smart categorisation: Incoming emails are automatically sorted into pre-defined categories, keeping your inbox clean and organised.
Context-aware replies: Cassie crafts personalised responses for emails that need your attention, using your company’s data and tone of voice from Brain AI.
Time-saving automation: You’ll handle leads and customer conversations faster with Cassie, while keeping the rest of your inbox easily manageable.
Limited Beta Access
As this is an early beta release, the feature is currently available to a limited number of users. We’ll gradually expand access as we refine and improve the experience.
Want to join the beta program?
Contact our customer support team to request early access!
Why use our Inbox Manager?
Managing a busy inbox doesn’t have to eat up your day. With our inbox manager, you can:
Focus only on emails that truly need your attention.
Respond to leads and existing customers up to 10x faster.
Maintain your brand voice effortlessly — every reply Cassie crafts reflects your tone, style, and business context.
Ensure no important message ever slips through the cracks.
Cassie transforms your Gmail into a productivity hub — a smarter and faster way to manage email.
How does Inbox Manager work?
Cassie analyses incoming emails: when a new email arrives, Cassie automatically categorizes it using your pre-defined labels. This allows her to instantly understand what type of message it is and which emails she needs to craft replies to.
Cassie gathers context from Brain AI: before replying, Cassie searches through your Brain AI knowledge base for relevant snippets - such as product details, contact information, or pricing.
Cassie crafts the reply: using the gathered context, Cassie writes a clear, natural, and human-sounding email reply — no templates or robotic phrasing. You can review and adjust her reply and, once you click "Send", the reply will be sent.
How to use our Inbox Manager?
Our Inbox Manager automation will take information from your Brain AI and auto-improve as you use it.
Inbox Manager setup
To set up Cassie's Inbox Manager on Sintra, do the following:
Pass the automation's onboarding and connect your Gmail.
Wait for the automation to load and connect.
Once you see checkmarks - the setup is complete.
After the setup, you can expect:
New additional labels in Gmail inbox
Last 10-20 received emails categorised in Gmail
Every new email received being categorised
Cassie's crafted replies to emails labeled as "To Respond", "Cold Email", or "Awaiting Reply."
Managing categorised emails
You can easily manage your labeled emails directly from your Gmail inbox — outside of Sintra:
Click on any label in Gmail to view all emails assigned to it.
Select all or specific emails you want to manage.
Use Gmail’s built-in tools to perform bulk actions — such as archiving, marking as read, deleting, or moving messages.
This lets you stay organised and handle multiple emails quickly, while Cassie keeps your labeling consistent and up to date.
Training Cassie for email replies
Cassie is designed to craft accurate, on-brand responses automatically — but the quality of those replies depends on the knowledge you provide in Brain AI.
While we’re still enhancing how you can train Cassie directly, you can already train her by adding and maintaining key information inside Brain AI. Do so by:
Adding snippets to Brain AI in Q&A format. For example:
Snippet title: What is the [business name] contact number?
Snippet description: The number for [business name] business is [insert phone number]
Snippet title: What is the price for [insert product/service]?
Snippet description: The price for [insert product/service] is [insert answer]
Using clear labels in snippet titles. This will ease the information maintenance in the long-run, ensuring Cassie has up-to-date information. There’s no strict naming rule — just make it clear and consistent. A little structure now saves a lot of confusion later. For example:
"[contact information]" - phone numbers, emails, addresses;
"[product info]" - product descriptions, pricing.
Editing the information when it changes. Outdated information = outdated replies. Cassie relies on Brain AI to generate accurate replies. If your business details, pricing, or policies change, make sure to update your snippets right away.
Read more about Brain AI knowledge management.
Inbox manager limitations
Since our AI-driven inbox manager is a completely new feature that's still being developed, there are some limitations you need to be aware of:
It only works with Gmail, other email providers are not supported and there is no ETA for when it will be available yet.
You cannot customise the email categories (labels) - they are pre-defined and cannot be changed. There's no plans to expand this functionality yet; however, if you see a need - fill in your request with the expected way of working in https://app.sintra.ai/wishlist and we'll acknowledge your requests when planning further enhancements!
Emails that do not require your replies will not be visible in Sintra: they will be available only in Gmail, keeping their labels and allowing you to easily filter the emails and perform inbox managing actions in bulk like deleting faster. You'll only be able to see emails labeled with "To Respond", "Cold Email", or "Awaiting Reply."
You cannot perform any bulk actions regarding email management in Sintra - you can only manag emails in bulk in Gmail.
You cannot read or attach files and/or images in inbox manager due to current integration limitations.
Continuous learning from your feedback on Cassie's replies is not available; however is planned for release in November, 2025. Until this article is updated to state otherwise, you can adjust Cassie’s performance by refining your Brain AI knowledge.
Auto-replying is not supported yet - in order for Cassie to send a reply, you will have to approve it manually.