Today my friend Mani called me and asked "Abbu, when i create any rules in outlook it's going as Client-Only Rule. Why so?" Then i asked him to share his screen to know what exactly the problem is. Finally i found out his requirement is like Moving the emails automatically to personal folder from inbox once it arrives with certain words in subject.
Now this is client only rule. Before i explain the reason let me say you what is the difference between client only and server based rules in outlook.
What is rules in outlook?
Rules are one of the powerful feature in Microsoft outlook. It is similar to filters in web mails such as Gmail/yahoo etc.,. We can setup rules such that if we receive emails from a particular person/with particular subject we can redirect to some folders in our mail box.
Server based Rules:
Server based rules are nothing but the rules which can run in absence of outlook execution. Server based rules can be configured such that the rules are defined on your mail servers. These rules are not machine dependent and it can it will be running from your mail servers.
Client only Rules:
Client only rules are something which cannot run when outlook is not in execution. Client only rules can be configured such that it fully depends on your local machine. These rules will not run automatically when outlook is closed.
Server based rule : If we need to move emails with subject which contains "SIFF" to a folder in the mail box called SIFF then it's a server based rule because it purely depends on the folder which is in your mailbox. This rule is ran in server as your mail box folder SIFF is defined in your mail server.
Client only rules: The same scenario if we wanna move emails with subject which contains "SIFF" to a personal folder(in your local machine) called SIFF, then it's a Client-only rule which will be inactive if outlook is not running. As personal folder(.pst) is the one which is referring to your local machine so this rule will need to refer to a file in your local machine. When outlook is closed it wont be able to refer to your local machine files. Hence outlook execution is mandatory.
Simple, A rule which runs within your mailbox is server rules, if a rule which depends on Personal folder(.pst) file on your local machine is client-only rule. Another example is if you wanna display desktop alert if we receive an email from particular person is a client only rule where as we are showing some alert on your local desktop and obviously the alert is needed for you to see it.
All client-only rules refers to your local machine only. In Mani's scenario he was trying to move emails with particular subject to his personal folder. As i said above it's referring to his local machine. This is client-only rule. Now he has created a sub-folder in his mail box and changed this rule into server based rule.
Thanks mani to make this as a topic in my blog.