While I was searching for the solution I found the KB articel on Parallels sites below:

http://kb.parallels.com/en/1147

Where they (Plesk adminstrators) have clearly mentioned that custom permissions set on top level folder like httpdocs, statistics, cgi-bin etc will get reset by Plesk. So I decided to make a test, I manually gave write permissions to httpdocs folder and ran webservmng.exe on it and yes it was removed. Then after allot digging I would that there us a file .Security which is saved under the folder with the domain name (parallel to httpdocs folder), that stores all permissions for that domain.

Before we start please be informed that these steps are applicable to Parallel Plesk version 8.4 and above as .Security file was introduced in 8.4 only.

So here are steps to get around the problem permanently:

1. Backup the .Security file and delete it from [drive]:inetpub/vhosts/domain_name, this file saves all the permissions assigned to that user from Plesk on Windows. Deleting it will remove all the records.

2. After renaming or deleting the . Security file, run this command below:

"%plesk_bin%/websrvmng.exe" --reconfigure-vhost --vhost-name=domain_name

3. This command will create a new .Security file with all default permissions on that domain.

4. Now login into Plesk >> Click on Domains >> domain_name >> File Manager >> httpdocs >> golden padlock of folder_name to set perm on >> “Advance” Button >> Select users >> Assign permissions >> OK.

These steps will save new permissions in .Security file and even if you run websrvmng on that domain again, the new permissions that has been set from Plesk will not get removed. There is no need to add any special group or users like, ASPNET or NETWORK SERVICE to any folder as those permissions are handled by IUSR_ & IWAM_/IWPD_ users.

Any permissions that has been assigned directly to httpdocs folder will get reset by Plesk and if you inherit them to sub folder, permissions from sub folder will also get removed.

So the moral is, DO NOT give any permissions from RDP, use File Manager option if you want to keep the trouble of permissions away.

Mail Server works with other programs in collaboration  to make up what we know as Messaging System. Messaging system must work without any flaws to keep smooth movement of Inbound and Outbound emails. Mail System uses following protocols to send and receive email messages.

SMTP (Simple Mail Transfer Protocol) – For Sending emails

POP3 (Post Office Protocol 3) or         -  For Receiving emails.

IMAP (Internet Message Access Protocol)

At any point you found out that emails are not reaching their destination, there are high chances of these emails would get stuck in Mail Queue. Only way to release emails from mail queue is to restart mail services. Restarting mail services is done from Mail Server. Make sure before restarting mail service you ask anyone who has good knowledge of doing it.

The process of direct linking to websites files such as images, videos etc is called as Hot Linking. It is like using an image (tag/image link) which you have found on someone else web page, and would be using on your blog. Every time the blog is browsed image will be shown because it is Hot linked from it’s original source.

This becomes a point of concern when your website is Hot linked by someone else.

Let me explain
Every website has a fixed bandwidth (bandwidth - Amount of data transferred from website to a users computer). When any internet user browses a website and if that website is hot linked to your site then your website’s
bandwidth is used in transferring the requested data.
??? => This means you are paying for the bandwidth which is not used by you.

To overcome Hot linking(Bandwidth Theft) Hotlink Protection is used. It prevents other websites from directly linking to files (as specified above) to your website.
Hotlink Protection can be set from Plesk Control Panel as well.