Outgoing emails wont send

Try these checks and fixes in order:

1. Confirm Outlook is online

• Look at the status bar at the bottom of classic Outlook.
• If it shows Disconnected, Working Offline, or Trying to connect…, go to Send/Receive tab > Work Offline to toggle back online, then try sending a new message again.

2. Verify internet connectivity

• Open a browser and go to http://www.microsoft.com or http://www.bing.com.
• If these do not load, fix the network connection first; Outlook cannot send new messages without internet access.

3. Check for a stuck large message

• Go to the Outbox folder.
• Open any stuck messages, especially the oldest one.
• If there is an attachment larger than about 20–25 MB, remove it, or upload the file to OneDrive and send a link instead, then resend.

4. Check Outlook.com limits and mailbox If using an Outlook.com/Hotmail account in New/Classic Outlook:

• Make sure the message (including attachments) is under 25 MB; larger messages will not send.
• If the Inbox is full, empty Junk Email (right‑click Junk Email > Empty folder) and delete unneeded items so new mail can be sent.

5. Try sending from Outlook.com web

• Sign in to Outlook.com in a browser and send a brand‑new email to the same recipient.
• If it also fails there, check for:
  • A non‑delivery report (NDR) explaining the issue (invalid address, recipient mailbox full, spam filter blocking, etc.).
  • If the address is correct but NDR persists, follow the guidance in Sender Support in Outlook.com from the referenced article.

6. Check antivirus and add‑ins (classic Outlook)

• Some antivirus products block sending after detecting a problem; follow the antivirus help to clear any issues.
• Start Outlook in safe mode to rule out add‑ins:
  • Press Windows key, type outlook.exe /safe, press Enter.
  • Try sending a new email. If it works in safe mode, create/repair the Outlook profile as described in the referenced article.

7. Repair Outlook / profile (classic Outlook) If new messages still fail while replies/forwards work:

• Run Repair on Office (this can take up to 30 minutes).
• If needed, repair or create a new Outlook profile and test sending again.

If none of these steps change the behavior, capture any error message shown when the new email fails and contact Microsoft support with those details.

References:

• I can't send or receive messages in Outlook
• Can't send or receive email in Outlook.com
• Outlook email stuck
• I can't send or receive messages with Outlook for Mac