How to message clients and share files privately

One private thread with each client on their portal page, with files both ways, instead of private papers sent by email.

Updated 2026-10-25

Each client can have one private thread with you, on their own portal page. You write from their card; they read and answer on the page, and either of you can add files: pictures, PDF, Word, Excel, PowerPoint, CSV or text. It saves asking clients to email private papers.

Messages are there when your business has quotes, jobs or invoices switched on, because they live on the customer portal. See how to give a customer their own portal.

Write to a client

Open the client from Contacts (your business may call it Customers or Clients).
If Customer portal says Make link, press it first. The client reads and answers on that page.
Under Messages, press Write to them (or Open messages once there is a thread).
Type your message. To send files with it, press Add files and pick up to 5.
Press Send.

Sending does not email the client. The message is on their page the next time they open it. To let them know, press Tell them by email: Otto drafts an email with the link to their page, never the message itself, and it waits in Reviews until you approve it. Pressing it again while one is waiting does not make a second email.

What the client sees

Their portal page shows Messages and files once you have written the first message. It opens the thread, where they can type an answer, add up to 5 files and press Send. Only they and your business see the thread. Opening the page changes nothing; only pressing Send does.

When a client writes, you get a notice, and their card shows Messages with how many are new. Opening the thread marks them read.

Share a note with the client

Notes on a client's timeline are private to your business. To let the client read one, such as what you agreed in a session, press Share with client under the note. A copy goes into their messages on their private page, from you; the note itself stays private and unchanged, and the timeline notes that you shared it. They need a portal link first. Nothing is emailed: press Tell them by email if you want them to know. A note can be shared once, and notes holding what someone typed into a form cannot be shared.

Every thread in one place

Contacts → Messages at the top lists every client with messages, newest first, with how many are new. Press one to open the client's card.

Good to know

A file that is not a picture, PDF, Office, CSV or text file is refused, and so is an Office file with macros. When one file is refused, the whole message is not sent, so nothing arrives half done.
A client can send up to 30 messages a day.
The thread shows the last 200 messages.
Turning off the portal link also closes the thread and its files for anyone holding the old link. Make a new link and the thread is there again.
Otto does not read, sort or answer these messages. Nothing a client writes can tell Otto to do anything.

If it doesn't work

Send grayed out with "Make their portal link first": press Make link under Customer portal on the card.
Tell them by email grayed out with "No email address saved": add an email to the client, or copy the portal link and send it yourself.
Tell them by email grayed out with "Write to them first": the email points to your message, so write one first.
The client says the page shows "not available": the portal link was turned off. Make a new one and send it.