Quick answer
If Outlook is not sending or receiving messages, first check your internet connection and account status, then the Outbox folder and rules. The cause is often incorrect server settings, a full mailbox or a security filter. Follow the steps in order and in most cases the problem is resolved without calling support.
How to recognize the problem
- Messages remain in the Outbox folder and are not sent.
- No new messages arrive, even though the sender claims they sent them.
- An error message appears when sending or receiving.
- Outlook shows "Working Offline" or "Trying to connect".
- No new messages in Junk Email or other folders.
Most common causes
No internet connection or unstable connection
Outlook cannot communicate with the server if the computer is not connected to the internet or the connection is interrupted.
Incorrect account settings
An incorrect server name, port or encryption method prevents sending and receiving. This often happens after a password change or update.
Mailbox is full
If the mailbox has reached its limit, the server rejects new messages and Outlook displays an error.
Rules or filters move messages
A rule can automatically move or delete incoming messages, so it appears they are not arriving.
Security software or spam filter blocks traffic
Antivirus, firewall or a server-side filter can block Outlook or mark messages as spam.
Step-by-step fix
- 1
Check your internet connection
Open a browser and try to load a web page. If it does not work, restart the router or connect to another network. In Outlook, check the status in the bottom right corner: if it says "Working Offline", on the
Send/Receivetab turn off offline mode, then pressF9. - 2
Check account status and password
Go to
File > Account Settings > Account Settings, select the account and clickRepair. If prompted for a password, enter it again. For a Microsoft 365 account, check that you are signed in underFile > Office Account. - 3
Review the Outbox folder
Open the
Outboxfolder. If there are stuck messages, open them and check that the addresses are correct. Try to send them again; if large attachments are the cause, remove the attachment or save the message text before deleting. - 4
Check rules and filters
Go to
Home > Rules > Manage Rules & Alerts. Temporarily disable all rules that move or delete messages and test. Also check theJunk Emailfolder and other folders where rules may move messages. - 5
Test sending and receiving
On the
Send/Receivetab, start send and receive or pressF9. Send a test message to yourself or a colleague. If it fails, note the exact error message. - 6
Check server settings
In
File > Account Settings > Account Settings, double-click the account and check the incoming and outgoing server details. For IMAP/SMTP check the ports (e.g. 993 for IMAP, 587 for SMTP) and encryption method. If you are not sure, contact your administrator. - 7
Temporarily disable antivirus or firewall
Temporarily disable antivirus or firewall and test Outlook. If it works, add Outlook to the exceptions or contact the security software manufacturer. Do not leave protection disabled for long.
- 8
Check mailbox size
If the mailbox is full, delete unnecessary messages or archive them. In Outlook you can use
File > Info > Tools > Clean Up Old Itemsor manually emptyDeleted ItemsandJunk Email. Before deleting, check that you need the messages, and if unsure, make a backup. - 9
Restart Outlook and the computer
Close Outlook, then open it again. If the problem persists, restart the computer. For stubborn cases, create a new Outlook profile in
Control Panel > Mail > Show Profiles.
If nothing helps
If you have gone through all the steps and the problem remains, check whether the problem is only on your computer or on the server. Try accessing mail via a web browser (e.g. Outlook on the web). If it works there, the problem is in the Outlook application or profile. If it does not work there either, contact your administrator or service provider. For Microsoft 365 accounts, check the service status in the Microsoft 365 admin center. As a last resort, create a new Outlook profile and add the account again. Do not forget to save a copy of your data before any major changes.
How to prevent it
- Regularly update Outlook and the operating system.
- Occasionally check account settings and password.
- Keep the mailbox below the limit and archive old messages.
- Disable unnecessary rules and filters.
When to call a professional
If you have checked all the basic steps and the problem still exists, or if it is a business account with multiple users, contact IT support to avoid data loss and longer downtime.
IT infrastructure maintenance · Servers, networks, backup, security and helpdeskFAQ
Why does Outlook not send messages but receives them?
The problem is most often in the outgoing server (SMTP) settings or in security software that blocks sending. Check the port and encryption method in the account settings.
How can you tell if the problem is with your computer or the server?
Try accessing mail via a web browser. If it works there, the problem is in the Outlook application or profile. If it does not work, it is probably the server or internet connection.
Is it safe to disable antivirus to test Outlook?
You can temporarily disable it for a few minutes for testing, but turn it back on immediately afterwards. If Outlook works, add it to the antivirus exceptions.