SMTP Time Out (0x8004210B) in Outlook 2007

[avvia]

I have been running Outlook 2007 on windows xp for several months with 3 SMTP Email accounts all functioning correctly.but suddenly i am getting the error code 0x8004210B.the emails are sent with no problems when i exit from the Outlook.Does anyone know what causes this issue and how to fix it?Any help will be extremely appreciated.

[Macarenas]

The error 0x8004210B occurs when the read receipt notification e-mail message is processed by a Microsoft Exchange 2000 Server computer by using the Simple Mail Transfer Protocol (SMTP) protocol with anonymous access authentication turned off.

[Glenny]

Do you have any firewall or antivirus installed on your PC and what is it?Try setting your timeouts to a higher value.

1) Verify POP / IMAP settings

2) Change outgoing port to 5125

3) Restart computer

[vishodhan]

This problem is corrected in Office XP Service Pack 3.To resolve this problem, obtain the latest service pack for Microsoft Office XP from Microsoft site .

check this thread with similar issue :

Error 0X8004210B in Outlook 2003
Outlook 2003 won't send in Vista

[JonathanD]

This error can be caused by a number of different things depending on the email software in use. Check the server port number. Gmail uses Server Port # 465 for SMTP.Possible fixes include recreating the account within your email software, re-configuring or disabling mail scanning software, and applying all available service packs/updates to Outlook/Outlook Express.