Outlook not sending group emails

Try these checks in order for Outlook for Windows home accounts:

1. Check whether the message is stuck in Outbox.
   • Open the oldest stuck message first.
   • If it has a large attachment, remove it and try again.
   • In Outlook.com, attachments larger than 25 MB cannot be sent.
   • In classic Outlook, large attachments can also block that message and later messages.
2. Make sure Outlook is online.
   • In classic Outlook, look at the bottom status bar.
   • If it shows Disconnected, Working Offline, or Trying to connect..., Outlook cannot send mail.
   • Go to Send/Receive and turn off Work Offline, then try sending again.
3. Force a send/receive.
   • In classic Outlook, go to Send/Receive > Send/Receive All Folders.
   • If needed, use the Sync button on the View tab to force a manual sync.
4. Check the recipient count and account sending limits.
   • If this is an Outlook.com family/personal account, sending to a group can hit temporary sending limits, especially after account changes or on accounts with lower sending reputation.
   • A group email counts toward sending limits by recipient.
   • Newer or recently changed Outlook.com accounts can have a lower temporary sending quota until account credibility increases.
5. If the message is being blocked only for group sends, split the group into smaller batches.
   • Send to fewer recipients at a time.
   • Avoid sending multiple large group messages back-to-back.
6. Check whether the mailbox is full.
   • If the inbox is full, Outlook.com cannot send or receive new messages.
   • Empty Junk Email if needed to free space.
7. If the account password was changed recently, sign in again in Outlook.
   • Outlook may prompt for the account password.
   • Complete the sign-in flow and retry.
8. If a non-delivery report appears, read the reason in that message.
   • Common causes include invalid addresses, recipient mailbox full, server issues, or spam filtering.

If the issue started after moving to a family account, the most relevant supported cause is that Outlook.com may be applying temporary sending restrictions or lower quota behavior. In that case, sending smaller batches and allowing time for the account to establish normal sending history is the supported workaround.

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