Before you begin:
Confirm the [dataset](🔗) you need is set up.
Create a segment or identify the segment you'll use. Write the segment name down; you'll need it soon.
Consider using an experiment to test the effectiveness of your flow prior to publishing it. <!-- is this terminology correct? Link -->
Consider what you want this flow to do. Explore **Flow Action Types** for options.
One-time send example
For this example, we'll set up a one-time message. This is the basic walkthrough for all flows, but for more details specifically on recurring flows, click here.
### Getting started
From the left navigation, click **Create Flow**. <!--- include screenshot --> You're presented a **flow name** field and **flow type** choices:

Choose **One-time**, then **Name** your flow.
Click **Start**. This flow screen displays:

As you complete each step, the next will become available. For example, after you complete **Configure Segment**, **Send Time** will come available.
### Configure Segment
Click the **drop down** then search for the segment you're targeting this message to. **Click** the name to complete the field:

If you're creating a triggered message, and you'd like to send a one-time message to any contacts currently in the segment too, select that here. <!-- add screenshot -->
### Send Time
Choose when you would like the flow action to be taken, either **Immediately** or **Send at a specific time** (complete your desired **Date**, **Time Of Day**, and **Time Zone**). The current time in your selected time zone displays below the field; the difference is based on your personal time zone as it's set by your admin.<!-- date is optional? --><!-- how to change my time zone?-->

Time Options Based on Flow Type
**One-time messages**: send immediately or schedule sends
**Triggered and Recurring messages**: select a time for the message to be sent each day <!-- each day of what? how long?--> Streams sync when your data is refreshed. <!-- what's a stream, link -->
To set a maximum number of sends per hour, expand **Advanced**: <!-- why would I do this?-->
Check **Spread out send over time**
Click the **arrows** to increase or decrease how many sends per hour. As you change the number of sends, a time estimate to complete this flow <!-- is this right?--> displays. <!-- based on what?-->

### Configure Testing and Branching (Optional)
If you don't want to run an experiment for this flow, click **No** and move on to step 10.
If you do want to run an experiment, click **Yes**. This screen displays:

For more information on how design and run an experiment, click [here](🔗).
### Configure Actions
Click the **+** to choose an action to take on your flow. If you change your mind, click **Delete** to remove it. You must choose at least one action. See **Flow Action Types** for a detailed breakdown of each option.
Click **OK**.
### Configure Data Feed (Optional)
Optionally, click **Yes** to configure a data feed to [export data](🔗) to an [Amazon S3](🔗) bucket or SFTP (Secure File Transfer Protocol) endpoint. If you don't want to configure a data feed, move on to step 14.

If yes,
Choose a **Data Format** (CSV, TSV, or JSONL).
Optionally, click the checkbox for **Hash identity using SHA-256**. <!--what do we use this for?-->
Choose a **Data Target** (S3 or SFTP).
For S3, choose an existing **Bucket** to export data to. <!-- who to contact if you don't see your bucket?-->
For SFTP, choose an existing **Host**. <!-- same question -->
Optionally, include a **Path**. <!-- what is this for?-->
Define any additional fields to include in the export. You can choose to:
Search and include an existing data feed <!-- what's this?--> or
Add fields individually by clicking **Add** then typing a **Name** and **Value**. Click the **bell icon** to turn off empty custom context alerting <!-- add a link-->.
If you're not ready to send, click **Save for Later**
If you're ready to send the message as you've configured, click **Send**.
## Spread out one time sends with a _throttled send_
Simon provides an option to spread out the send of **one-time messages** to avoid extreme peaks in traffic to websites, call centers, and apps.
Throttling is configured under _Send time_ in the flow builder. It is available for both immediate and scheduled sends. The rate is configured as a maximum number of sends per hour. When you set the send rate, you will see the approximate minimum time it would take to complete the send based on the current segment membership and the send rate. The maximum time that is allowed is 24 hours. Keep in mind that if the segment size changes substantially before the flow is launched, the actual duration may vary from the estimate provided.

After you launch a throttled send, the maximum hourly rate will be displayed along with the flow status. A throttled sends will show up as 'Syncing' for the entire duration from when the send starts until it has completed.

Example

Example
## Cancel a one time send
One-time messages can be cancelled at different stages.
### Scheduled send
Cancelling a scheduled send will return it to draft mode. It is the same as any other draft flow, so you can make any edits and schedule it again.
Cancelling when messages are queued in channel
For certain channels (including SendGrid), **scheduled** sends will get queued in channel to optimize delivery performance. You will not be able to cancel a send within Simon once the messages have been queued in the channel. If the flow has started syncing, cancelling will prevent any further messages from being queued in the channel. For more information on sync statuses, see [Sync Status](🔗)
### Send in progress
A one-time send can also be cancelled after it started syncing. This will prevent any additional messages from being sent to the channel, and you will be able to see what portion of your send went out.
