sharepoint 2007 - sending alert email to operator assigned

how can i create a workflow in sharepoint designer so that whenever an item in the list is assigned to a user. the user gets email.

here is how i am doing it

in my list there is a collumn called assigned operator while creating an item on this list the assigned operator is chosen from the active directory. Also there is 开发者_StackOverflow社区an option to chose multiple assigned operators.

i want that when an item in this list is created. the assigned operator only should get a standard email that a item has been assigned to you.

while creating a workflow using sharepoint designer , i select the option automatically start this workflow when a new item is created and press next

i chose action for step1 as send an email

i edit this message properties by

To field -> workflow lookup ->

chose the data source and the field to perform lookup on

Source : current item Field : ( Here lies the problem - i dont see the "operator assigned" field here , all i see is the fields - created by, file type, modified by, project name and a few others but the "operator assigned" field is missing.

can you help me

1. What is the type of "operator assigned" column? I added a "Person or group" field, it shows up in workflow designer. However, the value of such field is domain\username, not an email address.
2. Take a look at custom SharePoint activities from CodePlex There is this "Lookup user info" activity which allows to get the email, store it to a variable and then send e-mail.

There are couple environments on sharepoint, one of them not allowed to work on sharepoint designer, and modify things like a master page, the reason is that those sites are less flexible for design but easier to upgrade the version of the sharepoint environment, for example upgrade from SP2010 to SP2013.

So this is the reason that I couldn't see that option.