Pause, resume or stop a mail merge campaign

Pause to continue later, or cancel to stop generating the remaining emails. Neither action recalls sent emails or stops messages already scheduled with Microsoft 365. Download your report before starting another campaign.

What pausing or cancelling stops

SecureMailMerge generates messages in Outlook and submits them to Microsoft 365. Microsoft then sends them immediately or at their scheduled times. Pausing or cancelling stops the add-in from generating more messages. Messages already submitted can still send, including while Outlook is closed.

Pause and continue later

1. Select “Pause sending” in the campaign manager. The message currently being processed finishes before the campaign pauses.

2. Leave the campaign paused until you are ready to continue. Your original schedule is retained; resuming does not restart it from the current time.
3. Select “Continue sending” to process the remaining recipients.

If your campaign uses individual attachments, upload the files again when prompted. You must supply all files required for validation, including ones used by recipients already processed.

Resume after closing Outlook or the add-in

Reopen your template draft from Drafts, then start SecureMailMerge from the “Apps” menu. Continue the saved campaign instead of creating a new one or re-uploading the spreadsheet as a new campaign. Re-upload individual attachment files if prompted, then select “Continue sending”.

If the add-in warns that a submitted message’s progress could not be saved, keep the pane open until the warning clears. If it cannot confirm a message’s outcome after reopening, check your mailbox before resending and contact support. Do not assume an uncertain result means nothing was sent.

Cancel the remaining campaign

1. Select “Cancel campaign”. The add-in pauses while you confirm.
2. Select “Yes, cancel campaign” to finish the campaign without generating its remaining messages. Wait for the current operation to finish if the add-in asks you to.
3. Select “Download report” on the finished screen and save it before selecting “Start new campaign”.

A cancelled campaign cannot continue from where it stopped. The report keeps the outcomes of processed rows and marks unattempted rows as Cancelled.

Stop messages that are already scheduled

Cancelling the campaign does not remove messages already scheduled with Microsoft 365. Those messages must be deleted separately, and only deleting them in time prevents sending.

Your template draft and the generated recipient messages are different

• Your template draft is the email you composed and started SecureMailMerge from. It contains the personalization tokens, such as {{First Name}}, and is not sent to your recipients.
• The generated recipient messages are created by SecureMailMerge, one per recipient, with the tokens filled in. When a campaign is scheduled or delayed, Microsoft 365 holds each one in Drafts until its send time.

Deleting your template draft does not cancel the campaign or any generated recipient message. To stop scheduled emails, delete the generated recipient messages.

How to delete the scheduled recipient messages

1. Open Outlook on the web and sign in to the same sending mailbox (the Microsoft 365 account you signed in with in SecureMailMerge). If you changed “From” to an alias or a shared mailbox, the generated recipient messages are in the Drafts folder of the account you signed in with, not in the alias or shared mailbox.
2. Open the Drafts folder and find the campaign’s generated recipient messages. Each has a personalized subject, a single recipient’s address in “To” (plus any CC or BCC addresses from your template), and a scheduled send time.
3. Check the subject and recipients before deleting, so you do not delete your template draft or unrelated drafts by mistake.
4. Delete every generated recipient message you want to stop, before its send time. With “Delay between messages” or daily limits, each message has its own send time, so start with the earliest.
5. Refresh Drafts and confirm the deleted messages no longer appear there in Outlook on the web.

Do not open a generated recipient message and select “Send”, which sends it immediately.

If you delete the messages in a desktop Outlook client instead, the deletion may take time to synchronize with Microsoft 365, especially for a large campaign or large attachments. Check Drafts in Outlook on the web to confirm they are gone. A message is not cancelled if it has already been sent, or if the deletion did not reach Microsoft 365 before its send time, and sent messages cannot be recalled by pausing, cancelling or deleting drafts.

Where Outlook keeps scheduled messages

Outlook’s own scheduling features keep messages in different folders, which is easy to mix up:

• Classic Outlook “Delay Delivery” keeps a delayed message in your Outbox until its delivery time.
• New Outlook and Outlook on the web “Schedule send” keep a scheduled message in Drafts until its send time.

SecureMailMerge’s scheduled recipient messages are held by Microsoft 365 in Drafts, so look for them in Drafts in every client, not in the Outbox. Classic Outlook may not show their scheduled time, so use new Outlook or Outlook on the web to check it. Microsoft explains its own features in Delay or schedule sending email messages in Outlook.

Retry only the recipients who still need an email

Open the send report and review each outcome first. After fixing the reported problem, create a recipient spreadsheet containing only the rows you intend to retry, then start a new campaign and send a fresh test.

Uploading an unedited send report does not automatically retry failed rows. It is treated as an ordinary spreadsheet, so rows marked Sent can receive another email. Do not include Unverified rows until you have checked whether their messages were submitted, and do not retry scheduled rows merely because their delivery time has not arrived.