Hello,
My enterprise is a new combination of two exchange environments. One environment is Office 365 and the other a third-party hosted exchange environment. I am the admin for the Office 365 environment and do not have much data about the administration of the other environment.
In order to benefit from our SharePoint environment, many of the employees with the third-party hosted exchange email addresses now also have an Office 365 email address. Since they came into this combination with the third-party hosted exchange email address as their primary email address, they often forget to check their "new" email address.
I suggested forwarding their new Office365 address to their legacy address inbox using the forwarding provided in Office365's OWA.
There is a concern that if these emails are forwarded, they will not be secure.
From my research about Office 365, I believe all our outbound emails are sent encrypted based on opportunistic TLS. Any incoming email server also having TLS turned on will establish a secure TLS relationship thereby maintaining the encryption to the inbox of the recipient. Those who do not have TLS turned on, will receive the message sent by our server but it will be delivered with SMTP protocol without encryption.
We (our Office365 account) also have a license for FOPE. We use this protection for encrypting emails to clients without concern the TLS status of the recipient mail environment.
From all this background, my questions are as follows:
If the third-party hosted exchange environment has TLS turned on, is my suggestion (above) safe?
If they don't have the capability of turning on TLS, can we configure a rule in our FOPE license that will ensure all emails sent to their domain be encrypted thereby taking the burden off the sender to remember to always encrypt?
Or, if they are using Outlook 2010 with both email accounts defined, are they safe to create a rule that will move all the messages sent to their Office 365 inbox to their primary inbox?
Thank you in advance for your assistance!
msg