Port 38870 used by MAPI-PREOP Application - Possible Spam?

I've googled on this to no avail so am hoping that someone else here may have seen this.  

In checking my network traffic connections just now I came across a situation where a workstation at one of our remote sites is connecting to the server across port 38870 via the application MAPI-PREOP.  I'm not finding much information online about this port and am concerned that I may have a possible security issue.  The workstation is XP pro SP2 with the latest updates and McAfee virus catalog.   The server is SBS 2003, also with the latest updates.  

Please advise.   I could just block this port to see what breaks but would prefer to know in advance what it might impact.  
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

jeniehAuthor Commented:
Ok, in looking into it further one of our WAN Accellelleration devices creates this as a Mapi caching item so that users can load their email faster.   I'll request to have the question closed.  
Closed, 250 points refunded.
The Experts Exchange
Community Support Moderator of all Ages

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.