I am trying to find a way to forward the subject line of email to external email addresses.

Scenario:  I have contractors that only have email through OWA, they do not always check it obviously.  I need a tool that can forward the subject line only to an external email address outside the Exchange server.  Yes, it has to be subject line only.

Any assistance is greatly appreciated.

You could use a EWS script to stream notifications when a user gets a new email and have it copy the subject of the email and create a new email that includes that subject. Lots of EWS/PowerShell scripting but shouldn't be to bad. 

https://msdn.microsoft.com/en-us/library/office/dn458792(v=exchg.150).aspx

Hi Wargrym,

Thank you for your question.

You could use the link which DJ supplied to check if it could meet your requirement.

If not, we could create mail contact, then forward entire email to external email address. We could create mail account by the following link:

https://technet.microsoft.com/en-us/library/aa998858%28v=exchg.150%29.aspx

Then we could create email forward.

Notice: it will forward the all email to external instead of subject line.

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim