Channels
How WhatsApp, SMS, email, Telegram, Messenger, Instagram, comments and live-chat messages reach the Inbox, and the rules for each channel.
SmileLine connects your messaging channels into one shared Inbox: WhatsApp, SMS (via Twilio), Email, Telegram, Messenger, Instagram DMs, Facebook and Instagram comments, and Live chat (the website chat widget). This page explains how messages flow into the Inbox and what each channel allows, so you know what to expect when replying.
How conversations flow in
Once a channel is connected, inbound messages arrive in the Inbox automatically:
- A message from a number or address SmileLine already knows lands in that patient's existing thread.
- A message from an unknown sender opens a new conversation marked "Unknown contact" — link it to a patient so it lands on their timeline.
- A patient reply reopens a closed or snoozed conversation, so it always resurfaces in the Open tab.
Each patient has a single thread that can span channels. Their WhatsApp messages, texts and emails all appear in one conversation, and every message carries the icon of the channel it travelled on.
Replying STOP by WhatsApp or SMS immediately blocks that channel for the linked contact, even if the connection has just been paused or disconnected. Provider retries do not append another opt-out record. One shared contact can represent up to 25 patients. If a legacy contact exceeds that limit, SmileLine keeps the whole contact blocked while the patient links are reviewed. START can restore consent only through an active connection and cannot clear a block that still needs review.
Incoming WhatsApp or MMS attachments can briefly show Loading… while SmileLine copies them from the provider into durable storage. That copy is retried automatically if the provider or storage is temporarily unavailable. If the provider no longer makes the file available after all retries, the thread shows Attachment unavailable rather than loading forever.
SmileLine previews recognised image formats. Documents, active content and unknown file types download instead of opening as a page on the API origin.
Live chat threads come from the website widget. Replies you type are pushed to the visitor's browser in real time (with your first name, so they know a human joined), and the contact panel shows which page they're chatting from. Live chat is text-only — no attachments or templates — and the widget's own visitors show read ticks on your latest message once they've seen it.
Choosing a channel for a reply
When a thread spans channels, the composer's channel picker decides which one your reply rides. It defaults to the channel the patient last wrote on. A channel is unavailable when its connection is disconnected or the patient has opted out — the picker greys it out and shows the reason.
Channel rules
WhatsApp allows free-text replies only within 24 hours of the patient's last message (the "24-hour window"). While the window is open, the composer shows a countdown when it's about to close. Once it closes, the composer switches to approved templates only — pick one to restart the conversation, reply on another channel, or leave an internal note instead. Starting a brand-new WhatsApp conversation also requires an approved template. See Message templates.
Attachments are supported while the window is open.
Plain text only — no attachments and no subject lines. Sent through your connected Twilio number.
Supports subject lines, formatted content and attachments. When replying, leave the subject blank to continue the thread's latest subject. Long emails are collapsed in the thread — click Show full email to expand.
An outbound email can include up to 20 attachments, each no larger than 10 MiB and no larger than 25 MiB combined. An incoming email is limited to 25 MiB for the complete raw message and up to 20 attachments, each no larger than 10 MiB and no larger than 20 MiB combined.
For abuse and cost protection, each connected email address accepts a fair-use quota of up to 10,000 incoming messages or 10 GiB of raw email per UTC day, whichever is reached first. Mail above a limit is refused with an error naming the reason, so the sending server returns it to the sender rather than the message silently disappearing — nothing is ever partially imported.
When a page contains several exceptionally large formatted emails, SmileLine may show the safe plain-text version for later messages instead of loading more stored HTML. The message and its attachments remain in the conversation.
A connected Gmail or Outlook mailbox behaves the same in the composer, with replies sent from your own address and filed in the mailbox's Sent folder. Incoming mail written by a person creates or continues a conversation; newsletters, no-reply notifications, auto-responders and delivery reports stay in the mailbox and are skipped. Mail your team sends directly from Gmail or Outlook appears in the thread labelled as sent outside SmileLine.
Telegram conversations start with the patient: they message your practice's bot, and the thread appears in the Inbox. Replies go out as the bot, with no time window — you can reply whenever consent allows. New conversations cannot be started from SmileLine on Telegram.
Messages are plain text up to 4,096 characters. A reply can carry one attachment, and text sent with an attachment is its caption, limited to 1,024 characters — the composer refuses anything longer before it sends. Incoming photos, documents, voice notes and videos up to 16 MiB are copied into the conversation like WhatsApp media.
Messenger and Instagram direct messages allow replies only within 24 hours of the person's last message, with no template escape — once the window closes the endpoint shows Reply window closed and you reply on another channel instead. The composer shows a countdown as the window nears its end.
Replies staff type in Meta's own apps appear in the thread too, labelled sent outside SmileLine, so the conversation always reads complete. When someone unsends a message, the bubble becomes Message unsent — the history stays, the content goes. A reply can carry one attachment while the window is open.
Comments on your Facebook Page posts and Instagram posts arrive as conversations, one thread per person — all of someone's comments across posts share a thread, and each message notes which post it was on.
Replies are text-only and the composer offers two modes: Public reply posts under the comment; Private reply sends a one-time DM (Meta allows one private reply per comment, within 7 days). If the person answers your private reply, the conversation continues as an ordinary Messenger or Instagram DM thread. A comment the author deletes becomes Message unsent in the thread.
Attachment limits depend on the channel. Outbound email supports up to 20 files, 10 MiB per file and 25 MiB combined; incoming email allows up to 20 files, 10 MiB per file and 20 MiB combined.
Connecting and managing channels
Channels are set up in Settings → Channels by an owner or admin: connect a WhatsApp number, a Twilio SMS number, an email address or a Telegram bot, then use Test to verify the connection. The full setup walkthrough, including the webhook and inbound-address details your provider needs, lives in Settings → Channels.
If no channel is connected yet, the New conversation dialog will tell you — connect one in Settings → Channels first.