no that is not possible. The only way I know to send emails automatically is using the event based configuration, see https://docs.plm.automation.siemens.com ... tions.html
It also would not be so easy to do it, because where do you expect this should work? When you write something into a document, it is regarded as normal text. When you enter it into a work item field, it is work item content. It could work in the wiki if there was some support for that in velocity. But in all other places Polarion would always have to decide if you really mean to send a mail or not.
It works in Jira because there some text fields are regarded as kind of "scripted content". But I assume, also in Jira it only works for specific fields, like comments or description, although I have never tried to put something like that into a title field.
Maybe it would be possible to edit a custom field to a work item, with some script behind it, that triggers an email. But it would mean to implement something by yourself. And of course you could use the normal email triggering by assigning a work item to a user. You can even assign multiple users to mail to several people.
Please also check the last part of the help page; it states that users can switch off email notification, so it might not work for all users.