SMTP error

am from saudi arabia... Our company using webmail. Our mail service provided by from USA ... its working properly .....My boss using outlook 2007 and its working properly.. He traveled to USA for business trip... He have facing some problems with Outlook. He cant send email to others. Incoming is working...Email is receiving. But when he trying to send email to anywhere getting error like smtp is problem, contact with administrator or service provider. i check all configurations by remote desktop. i cant fix it. He can send and recieve email by web interface,, but from outlook he cant send emails...... So what is the problem for this?? anybody can help me ........How i can fix it...IF there is smtp blocking how i can confirm or how i can verify its smtp blocking ?? can we check using any commands for show block ports... if this we can identify i can tell to my boss , its not from our problem , its from isp or internet problem...  
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Alan HardistyCo-OwnerCommented:
If outlook is configured via SMTP / POP3, when the user travels to another location / country, he might find that SMTP port 25 is blocked as an anti-spam measure on the Internet provider that your boss is connected to.

The 'Best' way to use Outlook for people that travel is to use Outlook Anywhere (Outlook using RPC over HTTPS), which does not need port 25 to be opened and should guarantee being able to send and receive happily, no matter where your boss travels to.
nisartlaaAuthor Commented:
how i can configure RPC and HTTPS  instead of SMTP/POP3
Alan HardistyCo-OwnerCommented:
Do you know if your hosting company provide this to you as a service?  They might do, but may charge you more as a result.

If they do - they should be able to provide you with the required settings to configure Outlook correctly with their servers.
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nisartlaaAuthor Commented:
existing error how i can our MD is in business tour... he want send and receive emails by outlook...
Alan HardistyCo-OwnerCommented:
Talk to your mail provider and see if they have an alternative port that can be used to send email via, such as port 587 (Secure SMTP), then configure Outlook to use that port instead of port 25.

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You need to test that port 25 is working before you start changing things.  Use Telnet to send a email via port 25.  There is a how to guide here:

If you get communication errors then your port 25 is probably blocked.  If that is the case contact your Internet provider to have the block lifted.  Often this can involve moving to a slightly higher cost subscription package.

Agree with the comments posted by "Snibborg" & "alanhardisty:"

Regarding RPC over HTTP, if your company does provide service, you can follow below article to configure outlook 2007 (ask for the required settings from your company):

nisartlaaAuthor Commented:
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