One Time Sends

Launch a batched mailing in minutes

Once your campaign has been created, creative files uploaded and a credit card is on file for your account, you can launch your mailing via One Time Send. Before initiating, we recommend downloading and reviewing CSV file formats and guidelines:

Step 1: New One Time Send

Click into the campaign, navigate to the One Time Sends tab at the top and click New One Time Send.

Step 2: Creative Selection

Pick a Single Creative or Multiple Creatives if you intend on A/B Testing. Selecting the Multiple Creatives option will ignore any default creative settings.

Step 3: Mailing Recipients

If your creative uses custom merge tags, you will need to select Upload Addresses. Existing Audiences only store core mailing data, and any additional/custom columns were removed upon upload.

Send Sample

If you're interested in receiving a physical sample of your creative before launch, you can do so via the One Time Send option from within your campaign. Select Send Sample, then input the address for delivery:

Depending on mailroom policy, sending to a residential address may be more reliable than sending to an office building.

Once the mailing is done processing, you'll be able to see a preview of the mailer along with a delivery date estimate, and live status updates on where it is in the mail lifecycle from production to delivery from the campaign's History tab.

Upload Addresses

Uploading a mail file is the ideal choice for launching batched campaigns via One Time Send and are the only other option, aside from trigger setup, for supplying custom merge tag data. Pick Upload Addresses to drag & drop your address file.

Map File Columns

You'll be prompted to map your file columns to the required data for mailing, as well as any custom merge tags (if applicable). If any required data columns are missing, you will not be allowed to proceed to the next step. If any of the value in your data column are empty or improperly formatted, you'll see a warning but will be allowed to move forward.

Select Existing Audience

If you've already uploaded your audience file to the Audiences page, you'll see it available for selection if it has finished processing:

Do not select this option if your creative contains custom merge tags. The page Audiences does not store custom merge tag data, so your merge tags will not populate.

Select the Upload Addresses option instead.

Upload Emails for Address Enrichment

Email is the only required column for uploading email data for address enrichment. Including additional info such as name or phone number will not aid in the match process.

Typically, Poplar's address enrichment process sees a 50-70%+ match rate. In our internal tests we have generally found that older demographics tend to yield a higher match rate than younger ones. Thanks to the strict accuracy filters we've put in place, there should be a high yield of accurately matched addresses. Read More

Build a Lookalike Audience

Lookalike models are special, custom prospecting lists created from traits and/or behaviors identified within your existing customers. These can encompass purchasing behavior, interests, affinities, and additional predictive traits you wouldn’t initially think of.

pageLookalike Prospecting

Step 4: Address Validation

  • Total Records refers to the number of records in your file.

  • Mailable Records is the number of records from your file that can be mailed based on your Address Strictness setting. You can toggle here and decide which setting you want to use.

To ensure the highest likelihood of deliverability to we recommend the Strict setting. When mailing to commercial addresses, you may want to try adjusting to Normal or Relaxed depending on the confidence in your data. A CSV record of invalid addresses is available for download, this contains an explanation of the invalid tag if you'd like to review and make adjustments. Read More

Step 5: Holdouts

We highly recommend enabling a holdout percentage. Having incremental lift metrics will help you understand the true return on the campaign.

Step 6: Review & Finalize

Review all details before finalizing. You'll see a preview of the send and the final cost. If you do not have sufficient credit in your account, there will be an attempted charge to the card on file.

We recommend naming your send with a description, this is especially helpful if you plan to mail the same campaign more than once. Instead of creating multiple campaigns from scratch, you can launch multiple One Time Sends under the same campaign and adjust the campaign settings as you go, if necessary.

Step 7: Process Mailing

Once you click Process Mailing, there is a 30 minute grace period to cancel a send. Within this time-frame, head to the One Time Send Overview page to hit Cancel or Send Now. Just as with email, once the send has processed it cannot be reversed.

Track Your Campaign

Once your send has finished processing, head to the History tab to see a record of each individual mailer. Click into one of the items to see a PDF preview with the individual address data and merge tags applied, along with the Request Details and Event Log. The Event Log tracks each mailer as it moves through the mail stream, based on scans updated by the USPS.

Mail Lifecycle

A typical mailing transitions through a number of states during its lifecycle. These states indicate where it is in the preparation, production and mailing process. You can see many of these states when viewing a campaign on the web or when querying the API, this value is presented in the state field.

Campaign Mailing Status

To make it easier to see quick status of a campaign or one time send, we roll up one or more individual mailing states into easy to read groupings.




The mailing has been submitted to our API and is being validated. Here we may append an address, perform validation, and take holdouts.

In Production

The mailing has been sent to a print partner and is being produced. At this point a PDF and image of the final piece will be available for download.


The mailing has been printed and handed off to the USPS.


The mailing has been processed for delivery by the USPS. Typically it will arrive in the recipient's mailbox the same day or next day.


The mailing has been suppressed and will not be sent. Further detail is provided on the History page as to why the piece was suppressed.


The mailing was part of a holdout group and will not be mailed.


An error was encountered during processing. This may be further broken down by:








In some instances a mailing will never receive a USPS scan event and will be remain in the In Production state. Generally this should be under 5% for any given campaign but the piece would be expected to still be delivered in this instance.

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