Hey Brian! I don't think we support Message Recall in MAPI at this time but I'd like to do some testing on this to confirm and if not, get a request escalated to add support for it in the future. I'll follow up here once I get my initial tests completed to let you know my results. 

I just completed some initial testing on this for you and was able to replicate the behavior you outlined when recalling messages from one domain user to another via Outlook MAPI: I spoke with development on this and they confirmed that at this time we do not support Message Recall in that the message will be delivered once it hits the spool, there is no way for us to retroactively prevent delivery or remove the message from the user's mailbox at this time. This isn't to say it won't be supported in the future, but as of right now the physical removal of the message will not happen when recalled.

With that being said, the notice that goes out devoid of the recalling user's information is something we're going to look at so I'll get a task escalated to our developers for this now. Thanks for getting this reported!

No worries Kyle.

Both MAPI and webmail is affected. The images is from webmail.

I see that as well, so we are on the same page! :-) I did some testing against Exchange as well and I see there that this message never shows up in the user's inbox, so I'm thinking this message is actually meant to be processed by Outlook as an action rather than a notice when it is working correctly. I've escalated the issue report along with Exchange results so our development team can get to the bottom of it for you either way though so this should be headed in the right direction now. Have a good one!

Hi Brian, 

I wanted to let you know that Outlook's message recall won't be supported on the server or in other clients, as it's an Outlook-only feature. However, we have addressed the issue with the missing sender in the email. This fix will be included in our upcoming .NET Core BETA, which is expected in the coming weeks. 

Kind regards,