Error 0x80040201 reported in Microsoft Outlook when sending emails after removing exchange from outlook.

Task (MAIL – sending) reported error: 0x80040201 Unknown Error

Quote from Exchange Master :

This can happen if you disconnect Outlook from Exchange server and reconfigure it to use a local .pst file instead of an Exchange server mailbox. After this some Global Address list entries may stay cashed in Outlook client and will cause this error. Before sending the message Outlook will try to resolve all the recipients and since Global Address List is not available any more, it will report an error.

When you try to open properties for such address entry the following error will be reported:

The name or distribution list has been deleted and is no
longer a valid Address Book entry. The item could not be found.

They suggest that you delete the whole autofill cache to solve the problem. Deleting the whole autofil cache is not the only soluction. You can actually remove individual items in the cache list. An easy way to do it is to create a new email and start type in the “TO:“. Type A for example, allautofill suggestion that begin with A will show. Delete any items that do not show the email after the name. For example, you see, “Smith, John JSMITH“, “Smith, Martha < [email protected] >“, and  “Smith, Ron < [email protected] >“. The entry that had JSMITH instead of the email address is an exchange address and is not compatible with the POP3 mail server configuration. Just arrow down in the autofill list and then press the delete key on your keyboard to remove. Now that erroneous contact will not show again. Try sending the email again and this time it will go though.