Error Codes Library (Outlook)

Error Code

Meaning

Troubleshooting

Glossary

0x800CCC00

Authentication did not load (often invalid login or server issue).

Recheck email/password. If it persists, restart mail server or contact your ISP.

ISP: Internet Service Provider

0x800CCC01

Invalid certificate content for secured connection.

Verify intermediate certs are installed. If self-signed, install same cert on client and server.

Intermediate certificates: link your cert to the root CA

0x800CCC02

Invalid certificate date (expired/not yet valid).

Check certificate validity period; renew if expired.

Certificate validity period: timeframe the cert is valid

0x800CCC03

User already connected (another session is active).

Disconnect other session; close extra Outlook instances; try again later.

Session: one period of app interaction

0x800CCC04

-

-

-

0x800CCC05

Outlook is not connected to the server.

Check internet connection; if stable, server may be down—contact ISP/provider.

Server: computer providing data/services

0x800CCC06

-

-

-

0x800CCC07

-

-

-

0x800CCC08

-

-

-

0x800CCC09

-

-

-

0x800CCC0A

Message download incomplete.

Check internet; delete and re-download the email.

Download: getting data from server

0x800CCC0B

Server or maildrop busy (overloaded).

Try later; if persistent, contact ISP/provider.

Maildrop: stored mail waiting to be collected

0x800CCC0C

-

-

-

0x800CCC0D

Cannot locate server.

Verify server address/settings; confirm internet connection.

Server settings: required connection info

0x800CCC0E

Cannot connect to server.

Check internet, firewall, and server settings; server may be down.

Firewall: network traffic security system

0x800CCC0F

Connection dropped.

Check internet and email settings; may be server-side.

Server-side: performed on the server

0x800CCC10

Invalid email address.

Re-enter address; check for typos or missing parts.

Email address: identifier for a mailbox

0x800CCC11

Invalid address list.

Confirm all addresses are valid and correctly formatted; remove invalid entries.

Address list: mail-enabled recipients collection

0x800CCC12

Socket read error (can’t read from network).

Check network; restart PC; contact ISP if persistent.

Socket: a single network connection endpoint

0x800CCC13

Socket write error (can’t write to network).

Check network; restart PC; contact ISP if persistent.

Write: entering/sending data to a system

0x800CCC14

Socket initialization error.

Check network settings; restart PC; contact ISP if persistent.

Initialization: setting up required values/connections

0x800CCC15

Socket connect error.

Check network/settings; restart PC; contact ISP if persistent.

Network connection: link between devices

0x800CCC16

Invalid account on mail server.

Verify username/password with provider; confirm account exists.

User account: user profile on a server

0x800CCC17

User canceled operation.

Retry; if you didn’t cancel, check client/add-ins/network.

Email client: app used to manage email

0x800CCC18

Logon failure (unknown user/bad password).

Re-enter credentials; reset password if needed; contact ISP/provider.

Logon: signing in with username/password

0x800CCC19

Timeout.

Check network; server may be slow/overloaded—try later.

Timeout: wait limit before failure

0x800CCC1A

Security error (SSL/TLS problem).

Verify security settings; test disabling SSL/TLS temporarily to isolate cause.

SSL/TLS: secure communication protocols

0x800CCC1B

Server doesn’t support requested encryption type.

Match client encryption settings to server-supported settings; contact provider.

Encryption: converting info to secret code

0x800CCC1C

Not able to access the account.

Recheck credentials; account may be locked or server down.

Mail server: system that sends/receives email

0x800CCC1D

No server response.

Retry later; if persistent, contact email provider.

Server response: server reply to a request

0x800CCC1E

Unable to connect to the account.

Verify client settings (username/password/server); server may be down.

Connect: establish network communication

0x800CCC1F

Server response timeout.

Retry later; contact provider if persistent.

Server response timeout: no reply in time

0x800CCC20

Unable to find the email server.

Confirm correct server address; contact provider if persistent.

Server address: IP/URL identifying server

0x800CCC21

Server responded with an error.

Use the error message details; check settings; retry later if server issue.

Error message: message describing failure

0x800CCC22

Server response fail.

Retry later; contact provider if persistent.

Server response: server reply

0x800CCC23

Authentication failed.

Verify username/password; confirm auth method; contact provider if needed.

Authentication: verifying identity

0x800CCC24

Network connection failure.

Check internet; if other apps work, email server may be the issue.

Network connection: link between systems

0x800CCC25

SSL connection failure.

Confirm SSL configuration; test disabling SSL to isolate; fix cert/settings.

SSL: Secure Sockets Layer protocol

0x800CCC26

Unknown error.

Restart Outlook; contact provider if persistent.

Unknown error: root cause not identified

0x800CCC27

Out of memory.

Close apps; free RAM; consider system upgrade if persistent.

Out of memory: insufficient RAM

0x800CCC28

Server doesn’t support digital IDs.

Requires server setting change; contact provider/admin.

Digital ID: digital identity credential

0x800CCC29

User not authenticated on server.

Re-enter credentials; contact provider if it continues.

User authentication: confirming user identity

Error Code

Meaning

Troubleshooting

Glossary

0x800CCC40

Network subsystem is unusable.

Restart PC; reset network settings; check hardware; contact ISP if needed.

Network subsystem: OS networking components

0x800CCC41

Windows Sockets can’t support this app.

Confirm app is compatible with your Windows version; update app if available.

Winsock: Windows networking API/spec

0x800CCC42

-

Restart PC; install system updates.

-

0x800CCC43

Bad address.

Verify the IP address is correct.

IP address: numerical device network label

0x800CCC44

Unable to load Windows Sockets.

Reinstall network adapter drivers; reset network; OS repair/reinstall if needed.

Network adapter drivers: enable networking hardware

0x800CCC45

Operation in progress (blocking Winsock call conflict).

Avoid parallel blocking ops; reorganize code/operations to prevent conflict.

Blocking operation: halts execution until condition met

Error Code

Meaning

Troubleshooting

Glossary

0x800CCC60

Invalid response.

Verify SMTP server settings; reconfigure SMTP if needed.

SMTP: Simple Mail Transfer Protocol

0x800CCC61

Unknown error code.

Restart Outlook/PC; contact email provider if persistent.

-

0x800CCC62

Syntax error returned.

Check email content/format for unusual characters/structure; retry.

Syntax error: incorrect command structure

0x800CCC63

Parameter syntax incorrect.

Verify SMTP command/config; check content/configuration.

Parameter: value provided to a command

0x800CCC64

Command not implemented.

Server may not support the command; confirm SMTP server capabilities.

Command: directive to perform an action

0x800CCC65

Improper command sequence.

Commands sent out of order; verify SMTP process/config.

-

0x800CCC66

Command not implemented.

Confirm SMTP server supports requested command.

-

0x800CCC67

Command not available.

Server doesn’t support command in current context; verify SMTP stage/config.

-

0x800CCC68

Mailbox locked/busy.

Wait and retry; contact provider if persistent.

Mailbox: destination for email delivery

0x800CCC69

Mailbox not found.

Verify recipient address; recipient server may be misconfigured.

-

0x800CCC6A

Error processing request.

Server-side issue; retry later; contact provider if persistent.

-

0x800CCC6B

Mailbox exists but not on this server.

Verify correct SMTP/server routing settings.

-

0x800CCC6C

No space to store messages.

Recipient mailbox is full; retry later or ask recipient to free space.

SMTP: sending/receiving email protocol

0x800CCC6D

Storage limit exceeded.

Server-side mailbox/storage exceeded; retry later or contact admin/ISP.

ISP: Internet Service Provider

0x800CCC6E

Invalid mailbox name syntax.

Verify recipient email format; correct and resend.

-

0x800CCC6F

Transaction failed.

Check internet, server settings, and Outlook config; retry.

-

0x800CCC78

Unknown sender (Reply-To incorrect).

Verify Reply-To field contains a valid email address.

-

0x800CCC79

Server rejected recipients.

Verify recipient addresses are valid and formatted correctly.

-

0x800CCC7A

No sender address specified.

Confirm your outgoing mail settings include your email address.

-

0x800CCC7B

No recipients specified.

Add at least one valid recipient before sending.

-

Error Code

Meaning

Troubleshooting

Glossary

0x800420CB

Mail cannot be stored on server.

Check mailbox quota/storage; verify server settings; contact provider.

POP3: Post Office Protocol 3

0x800CCC90

Client response invalid.

Review client config; check conflicts/network issues.

-

0x800CCC91

Invalid username or user not found.

Double-check username; confirm account exists on server.

-

0x800CCC92

Password not valid for account.

Re-enter/reset password; update Outlook account settings.

-

0x800CCC93

Unable to interpret response.

Verify client config; check software conflicts/network issues.

-

0x800CCC94

STAT command required.

Ensure client issues STAT first; verify POP3 compatibility/config.

STAT: POP3 mailbox status command

0x800CCC95

No messages on server.

Confirm mailbox has new messages; contact provider if unexpected.

-

0x800CCC96

No messages marked for retrieval.

Ensure retrieval options are correct; retry.

-

0x800CCC97

Message ID out of range.

Verify message ID exists on server; retry.

-

Error Code

Meaning

Troubleshooting

Glossary

0x800CCCD1

Login failed.

Verify username/password and IMAP settings; contact provider if needed.

IMAP: Internet Message Access Protocol

0x800CCCD2

Message tagged (server not responding as expected).

Check server status/network; retry after stable connection.

-

0x800CCCD3

Invalid response to request.

Verify request syntax and client compatibility with server IMAP version.

-

0x800CCCD4

Syntax error.

Confirm IMAP command/response syntax; fix client config.

-

0x800CCCD5

Not an IMAP server.

Verify server settings and selected protocol (IMAP).

-

0x800CCCD6

Buffer limit exceeded.

Could be server load/config; contact provider/admin.

-

0x800CCCD7

Recovery error.

Contact provider; mailbox/server recovery issue.

-

0x800CCCD8

Incomplete data.

Check network stability; verify server status.

-

0x800CCCD9

Connection not allowed.

Server restriction/security; contact provider/admin to allow IMAP connection.

-

0x800CCCDA

Unknown response.

Verify client/server compatibility; contact provider if persistent.

-

0x800CCCDB

User ID changed.

Update user ID in Outlook account settings; contact provider if unsure.

-

0x800CCCDC

User ID command failed.

Verify command syntax/config; check server/network.

-

0x800CCCDD

Unexpected disconnect.

Check network interruptions; retry; monitor for repeats.

-

0x800CCCDE

Invalid server state.

Server-side conflict; contact provider/admin.

-

0x800CCCDF

Unable to authorize client.

Verify auth method, username/password; confirm server supports auth type.

-

0x800CCCE0

No more authorization types.

Change authentication setting to a supported method; contact provider.

-

Error Code

Meaning

Troubleshooting

Glossary

0x800CCCA0

News server response error.

Check network/server settings; verify authentication; retry.

-

0x800CCCA1

Newsgroup access failed.

Confirm group exists and permissions; verify settings.

-

0x800CCCA2

LIST command failed.

Verify command syntax and server compatibility; check connectivity.

LIST: retrieves available newsgroups

0x800CCCA3

Unable to display list.

Check client config/server auth; retry.

-

0x800CCCA4

Unable to open group.

Verify group name and permissions; contact provider if needed.

-

0x800CCCA5

Group not on server.

Confirm group exists; correct spelling.

-

0x800CCCA6

Message not on server.

Verify message ID and syntax; contact provider if needed.

-

0x800CCCA7

Message header not found.

Verify message ID; check server availability.

-

0x800CCCA8

Message body not found.

Verify message ID; check server availability.

-

0x800CCCA9

Unable to post to server.

Verify posting permissions/auth; check client/server settings.

-

0x800CCCAA

Unable to post to server.

Same as above: verify permissions/auth; retry after stable connection.

-

0x800CCCAB

Unable to display date.

Verify message ID; check server issues; retry.

-

0x800CCCAC

Unable to display headers.

Verify message ID; check server issues; retry.

-

0x800CCCAD

Unable to display MIME headers.

Verify message ID; check server issues; retry.

-

0x800CCCAE

Invalid user or password.

Verify credentials; correct typos; confirm auth requirements.

-

Error Code

Meaning

Troubleshooting

Glossary

0x800CCCC2

RAS/DUN not installed.

Install/enable RAS/DUN components.

-

0x800CCCC3

RAS/DUN process not found.

Ensure required processes are running; restart PC.

-

0x800CCCC4

RAS/DUN error returned.

Review related error details; troubleshoot based on returned error.

-

0x800CCCC5

ConnectOID damaged or missing.

Verify configuration; repair missing/corrupt ConnectOID files/settings.

ConnectOID: connection object identifier

0x800CCCC6

Error getting dial settings.

Verify dial-up config; check modem/adapter; correct settings.

-

Status Code

Meaning

Troubleshooting

X.0.0

Other undefined status.

Check for extra server details; consult RFC if needed.

X.1.0

Other address status.

Verify address format and syntax.

X.1.1

Bad destination mailbox address.

Correct recipient address; confirm mailbox exists.

X.2.0

Bad destination system address.

Verify the destination system address.

X.1.3

Bad destination mailbox syntax.

Fix recipient formatting/invalid characters.

X.1.4

Destination mailbox address ambiguous.

Use a more specific/unique recipient address.

X.1.5

Destination mailbox address valid.

No action required.

X.1.6

Mailbox has moved.

Update to the recipient’s new mailbox location/address.

X.1.7

Bad sender mailbox address syntax.

Fix sender address formatting/invalid characters.

X.1.8

Bad sender system address.

Verify sender system address.

X.1.9

Message relayed to non-compliant mailer.

Contact mailer administrator.

X.2.0

Other/undefined mailbox status.

Check extra server details; consult RFC if needed.

X.2.1

Mailbox disabled, not accepting messages.

Contact recipient/admin to enable mailbox.

X.2.2

Mailbox full.

Ask recipient to free space or increase quota.

X.2.3

Message length exceeds limit.

Reduce message size/attachments.

X.2.4

Mailing list expansion problem.

Verify list and recipients; contact list admin.

X.3.0

Other/undefined mail system status.

Check extra server details; consult RFC if needed.

X.3.1

Mail system full.

Contact admin; resend later.

X.3.2

System not accepting network messages.

Verify system availability; contact admin.

X.3.3

System not capable of selected features.

Adjust message/features to supported options.

X.3.4

Message too big for system.

Reduce message size; contact admin for limits.

X.3.5

System incorrectly configured.

Contact admin to correct configuration.

X.4.0

Other/undefined network/routing status.

Check extra server details; consult RFC if needed.

X.4.1

No answer from host.

Verify host availability and network connectivity.

X.4.2

Bad connection.

Resolve network connectivity issues.

X.4.3

Routing server failure.

Verify routing configuration; contact admin.

X.4.4

Unable to route.

Verify recipient address and routing setup.

X.4.5

Network congestion.

Retry later or during off-peak hours.

X.4.6

Routing loop detected.

Fix routing configuration to remove loop.

X.4.7

Delivery time expired.

Resend or contact admin.

X.5.0

Other/undefined protocol status.

Check extra server details; consult RFC if needed.

X.5.1

Invalid command.

Verify and resend with valid command.

X.5.2

Syntax error.

Correct syntax; ensure protocol compliance.

X.5.3

Too many recipients.

Reduce recipients or split into multiple emails.

X.5.4

Invalid command arguments.

Fix arguments; ensure they’re accepted by server.

X.5.5

Wrong protocol version.

Use a compatible protocol version.

X.5.6

Auth exchange line too long.

Shorten/split auth exchange if possible.

X.6.0

Other/undefined media/content error.

Check extra error details; consult RFC if needed.

X.6.1

Media not supported.

Change media type/format to supported option.

X.6.2

Conversion required but prohibited.

Confirm domain/alias and policy restrictions.

X.6.3

Conversion required but not supported.

Use a supported conversion method/format.

X.6.4

Conversion with loss performed.

Adjust conversion method to avoid data loss.

X.6.5

Conversion failed.

Verify conversion settings and compatibility.

X.6.6

Message content not available.

Confirm access permissions and content availability.

X.7.0

Other/undefined security/auth failure.

Check extra error details; consult RFC if needed.

X.7.1

Delivery not authorized; message refused.

Review auth/policy compliance.

X.7.2

Mailing list expansion prohibited.

Confirm server policy; adjust list usage.

X.7.3

Security conversion required but not possible.

Verify security conversion requirements/capabilities.

X.7.4

Security features not supported.

Use supported security mechanisms.

X.7.5

Cryptographic failure.

Verify crypto settings and certificates.

X.7.6

Crypto algorithm not supported.

Select supported algorithm.

X.7.7

Message integrity failure.

Verify integrity controls and signing settings.

X.7.8

Trust required / invalid credentials.

Fix trust relationship and credentials.

X.7.9

Auth mechanism too weak.

Upgrade to stronger auth method.

X.7.10

Encryption needed.

Enable encryption.

X.7.11

Encryption required for auth mechanism.

Enable encryption to use that auth method.

X.7.12

Password transition needed.

Complete password transition steps with admin/provider.

X.7.13

User account disabled.

Enable account or contact admin.

X.7.14

Trust relationship required.

Establish trust relationship required by server.

X.7.15

Authentication credentials invalid.

Correct credentials.

X.7.16

Per-user message quota exceeded (future release).

Reduce usage or increase quota.

X.7.17

System message quota exceeded (future release).

Increase system quota or reduce volume.

Error Code

Meaning

Troubleshooting

0x0004b9

-

-

0x000501

-

-

0x80000003

-

-

0x80004001

Not implemented.

-

0x80004005

The operation failed (often virus scanner/script blocking).

Check virus scanner integration; review script blocking/add-ins.

0x800300FD

Unknown error (insufficient Temp space).

Empty Deleted Items; clear Temp folder: C:\Windows\Temp.

0x80040109

Message changed (often virus scanner/add-ins altered message).

Disable conflicting add-ins/virus scanner email integration; retry send.

0x8004010F

Exchange Offline Address Book (OAB) URL not found.

Verify OAB publication address in Exchange.

0x80040115

Exchange server unavailable; Outlook must be online.

Check connectivity; ensure Outlook is online; can also occur with non-Exchange servers.

0x80040119

Unknown error (messaging interface; possible PST issues).

Check virus scanner integration; repair PST if applicable.

0x8004011D

Server not available.

Check connectivity; ensure Outlook is online; can also occur with non-Exchange servers.

0x80040126

Connection to server is offline (Outlook Connector issue).

Update Outlook Connector; remove and re-add Hotmail account.

0x80040305

Limited number of simultaneous items (often large email / Google Apps Sync).

Contact mail admin for server limits; reduce mailbox load if needed.

0x80040600

Unknown error (often auth / PST issues).

Check virus scanner integration; repair PST if applicable.

0x80040607

Unknown error (SMTP auth not enabled).

Enable SMTP authentication for configured SMTP server.

0x8004060C

Unknown error.

-

0x80040900

-

-

0x80040FB3

Error encountered (often BlackBerry/BES sync or corrupted item).

Confirm account association; remove corrupted item; retry sync.

0x80042108

Can’t connect to incoming (POP) server.

Contact server admin/ISP; verify POP settings.

0x80042109

Can’t connect to outgoing (SMTP) server.

Contact server admin/ISP; verify SMTP settings.

0x8004210A

Timeout from receiving (POP) server (often virus scanner integration).

Check virus scanner/add-ins; verify POP server availability.

0x8004210B

Timeout from sending (SMTP) server; possible malformed distribution list entry.

Check virus scanner/add-ins; rebuild or fix distribution list addresses.

0x80042112

-

-

0x8004218

-

-

0x80048002

Task canceled before completion (often add-ins/virus scanner).

Disable add-ins or virus scanner email integration; retry.

0x8004DF0B

-

-

0x80070005

Insufficient permissions (PST/OST delivery location issues).

Run scanpst.exe/scanost.exe; verify read/write permissions; verify file path; confirm OST belongs to correct user/mailbox.

0x8007000E

-

-

0x80070021

-

-

0x80070057

Invalid parameter values (often virus scanner or Google Apps Sync RSS sync).

Disable conflicting add-ins/virus scanner; review RSS sync settings if applicable.

0x80072F17

Sync could not be completed (often SSL certificate).

Check SSL certificate validity and trust chain.

0x8007007E

Unknown error.

-

0x80090FB3

-

-

0x800C0131

Unknown error (data storage).

Check storage health; repair data files if applicable.

0x800C0133

Unknown error (data storage; sometimes virus scanner).

Check storage + virus scanner integration.

0x800C013B

-

-

0x800CCC33

Access denied / Forbidden (Hotmail without Outlook Connector).

Install Outlook Connector for Live Hotmail account connection.

0x800CCC7D

Unknown error (SMTP server doesn’t support secure connections).

Disable secure SMTP or use supported security settings; contact ISP/provider.

0x800CCC80

None of client auth methods are supported by server.

Change authentication method or server; confirm supported auth with provider.

0x800CCCF7

-

-

0x81FC0005

-

Close and reopen Outlook.

0x834005

-

-

0xC0000005

-

-

0xD4904005

-

-