Guide
Build or buy an AI email assistant?
Most businesses do not need another software product to maintain. They need a better way to handle the customer requests, supplier updates, order changes and documents that arrive in email every day. That is the real question — not whether a model can summarise an email, but whether your advantage depends on deep, bespoke automation inside your own systems, or whether your team simply needs to understand and act on email better this month.
Last reviewed .
Definition
Start with the work that already arrives in email
Operational work rarely reaches a team in a neat form. It arrives as a customer asking for a revised quote, a supplier moving a delivery date, an invoice attached to a three-line message, or a long thread in which one sentence changes the agreed quantity. Five everyday jobs stand between that and anything your systems can use — and Kerna does all five.
- Summarising email threads, at three depths, so the current position is clear.
- Categorising incoming mail against five built-in categories, six of your own, or one of twenty industry sets.
- Translating messages across 45 languages, where language is what slows the work down.
- Extracting named fields from PDF, DOC and XLS attachments, exported to Sheets, Docs, Excel, Word or CSV.
- Preparing reply drafts across seven tones and eight intents, for the user to review and send.
The problem
A demonstration is not a workflow
An internal prototype can produce an impressive result in an afternoon. The consequential question is what makes it useful on the four hundredth message, for people who now depend on it. Three things separate the two.
It has to live where the work starts
The inbox, not a separate console. A workflow that asks people to forward mail somewhere, or to paste a thread into a box, adds a step to the job it was meant to shorten — and a tool that costs more effort than it saves gets abandoned rather than reported.
It has to handle what people actually send
Long threads, mixed languages, a revised order in a PDF, a spreadsheet of line items, the same conversation running in two languages at once. A tool that works on one carefully chosen example is a different thing from one that holds up across customer service, sales, purchasing, operations and finance.
It has to keep working as the business changes
Email patterns shift, commercial priorities move, people change roles. Someone has to own the prompts, the model costs, the evaluation and the failure cases — indefinitely. That is the part build estimates tend to leave out.
What it takes
Why starting with Kerna is the commercially sensible move
It lets a team improve a visible, recurring part of its work without first turning that improvement into an internal software programme.
You can test it before the budget conversation
Install Kerna into Gmail or Outlook from the marketplace, point it at a complex thread, an incoming document or a reply that needs care, and judge the result against your own work. Starter is €0 and includes every feature, so the first honest test does not need a purchase order behind it.
It works alongside the systems you already trust
Kerna prepares information before it reaches your ERP, CRM, spreadsheet or process. Your existing system stays the place for the record and the next operational step. Nothing is migrated, nothing is replaced, and your commercial and operational controls stay exactly as they are.
Control stays with the people answerable for the outcome
AI helps most in operational email when it makes the work easier to review, not when it quietly makes commitments on a team’s behalf. Kerna prepares summaries, categories, extracted fields and drafts; you decide what the thread means, what to promise and whether the reply is right. Kerna does not send mail itself.
It is the work, not a project
Nobody has to be assigned to it, no sprint is spent on it, and there is no internal tool whose owner leaves in a year. The team uses it on the mail they already have, and the part of the job that gets better is the part they do every morning.
Side by side
What each option puts on you
The same five-part job either way. What differs is who builds it, who keeps it working, and what you can change.
| Area | Building it yourself | Kerna |
|---|---|---|
| Getting started | Design, build and deploy an application, then get it in front of the people who will use it. | Install an add-in from AppSource or the Workspace Marketplace, subject to whatever your organisation requires of add-ins. |
| Living in the inbox | Build and maintain the mail integration, the permissions and the panel people work in. | Runs in the Gmail or Outlook the team already has open. |
| What it does | Every capability is one you scope, build and test. | Thread summaries, categorisation, translation, extraction from attachments and reply drafts, as shipped. |
| Fitting your business | Any logic you can specify, and any connection to your own systems. This is the real argument for building. | Configuration inside what the product does: your own categories, the fields you want out of a document, tone and intent. |
| Keeping it working | Yours: the code, the infrastructure, the prompts, the evaluation and the failure cases, as the business changes. | The vendor’s. What you own is deciding whether the output is right. |
| What it costs | Build, infrastructure, model usage, and the engineering time that does not stop after launch. | A plan, and the time it takes a team to pick it up. Starter is €0. |
Checklist
A practical way to assess the decision
Four questions, answered honestly about your own business.
- 1Does our problem begin with people having to interpret external email and attachments?
- 2Would clearer thread summaries, meaningful categories, extracted fields and reviewed drafts improve the work this month?
- 3Does the next step already have a home in our ERP, CRM, spreadsheet or operating process?
- 4Is the distinctive value we need truly deep system automation — or simply better preparation before that system is used?
Kerna
When bespoke automation earns its place
There are cases where building is the right strategic call. If the value depends on tightly automating a specialised internal process, connecting deeply to proprietary systems, or applying business logic that exists nowhere else, bespoke software may well be justified. That is a different need from improving the daily reading, sorting, document handling and response preparation that begins in email.
- Build where your own systems and logic are the product, and the automation is the differentiator.
- Use Kerna where the work is universal but time-consuming: making incoming email and documents understandable and ready for the next person or process.
- If the first three checklist answers are yes and the fourth is "better preparation", Kerna is the direct starting point.
- Kerna runs on Cloud Run in Belgium with Firestore in Poland, and personal data is redacted before content reaches the model. Whether that meets your own requirements is set out clause by clause on the trust page.
Questions
Questions people ask
- Is Kerna an alternative to our ERP or CRM?
- No. Kerna works before those systems, making the information arriving in email and attachments clear and usable. Your team then moves it into the process and system you already use.
- Does Kerna make commercial decisions or send replies?
- No. Kerna prepares drafts for the user to review and send, and does not send mail itself. Your team retains control of the decision, the wording and the final send.
- Who benefits most from Kerna?
- People whose real work arrives through external email: customer service, sales, account management, purchasing, supply chain, operations, order management, finance, and small teams handling important customer or supplier communication themselves.
- Does Kerna work in the tools our team already uses?
- Yes. Kerna is an AI email assistant for Gmail and Microsoft Outlook, installed from the Google Workspace Marketplace or Microsoft AppSource, working directly in the inbox.
Read next
Where to go from here
Before your ERP or CRM
The stage a build would be replacing.
Operational inbox management
The category, and the four jobs it asks for.
Customer and supplier email
What the work looks like, followed through one changed order.
Where your email goes
Processing, retention and redaction, clause by clause.
Pricing
What each plan includes, and the allowance on each.
Decide it against your own inbox
Whatever you conclude, conclude it against real mail rather than a demo. Install Kerna on the Gmail or Outlook you already use, take the next order change that arrives with a document on it, and run the whole thing — summary, categories, extraction, export, draft. Starter is €0 and includes every feature, with a trial token allowance to run them on.