Does moving emails to JunkEmail folder via EWS automatically block future messages from sender?

[Stella_Dreamer]

I’m working on an email application that uses the EWS API. I found out that I can transfer messages between folders using the Move method. I see there’s a folder called JunkEmail in the WellKnownFolderName options.

My question is about what happens when I move an email to this JunkEmail folder. Will the mail server automatically start blocking future emails from that same sender address? Or is JunkEmail just another regular folder like Inbox or Sent Items?

MailItem message = MailItem.Bind(exchangeService, messageId);
message.Move(WellKnownFolderName.JunkEmail); // Will this trigger spam filtering?

I want to understand if moving emails there has any special behavior or if it’s treated like any other folder move operation.

[JumpingMountain]

I’ve worked with Exchange environments quite a bit, and the JunkEmail folder acts weird depending on how messages get there. When you move emails using EWS, it doesn’t trigger the learning that happens when users hit ‘Mark as Junk’ in Outlook. Exchange’s spam filter learns from user clicks but treats API moves as basic folder shuffling. If you actually want to affect spam filtering, use the MarkAsJunk operation in EWS instead of just moving the message. This lets you block the sender and add them to the blocked list - which sounds like what you’re after for automatic blocking.

[Luna23]

nah, moving emails to the junk folder via code doesn’t actually trigger spam filtering. it’s not the same as marking them junk manually in outlook. it’s just a folder move with no extra rules applied.

[mikezhang]

I’ve built similar functionality before. The Move operation treats JunkEmail like any other folder - no special processing happens. Here’s what other responses missed: Exchange has blocked sender lists at both user and organization levels. When you move messages programmatically, you’re skipping the client-side logic that usually updates these lists. The server won’t block future emails from that sender because it doesn’t know why you moved the message. If you actually want to prevent future emails from specific senders, you’ve got two options: use MarkAsJunk with the block sender parameter set to true, or directly update the user’s blocked sender list through EWS. Just moving to JunkEmail organizes things visually but gives you zero filtering benefits.