Microsoft Outlook – Use Ignore or Clean Up Conversation to delete redundant messages

The Ignore Conversation or Clean Up Conversation feature in Outlook can reduce the number of messages in your mail folders.

Ignore command moves the whole Conversation and any future messages that arrive in the Conversation to the Deleted Items folder. 

Clean Up Conversation moves redundant messages throughout a Conversation to the Deleted Items folder, and keeps only the most recent message that includes the whole Conversation.

What is a conversation?

You might know a Conversation by the term email thread. A Conversation is the complete set of email messages from the first message through all responses. The messages of a Conversation have the same subject.

For example:

When you send a message to someone and then they reply, a Conversation results. In many Conversations, there might be many replies back and forth. Multiple people might reply to different messages in the Conversation.

What does Conversation Clean Up do?

Conversation Clean Up evaluates the contents of each message in the Conversation. If a message is completely contained within one of the replies, the previous message is deleted.

For example -

Jeff sends a message to Anne and Tim. Anne replies to both Jeff and Tim and in her Outlook message body, Jeff’s complete original message is included.
Tim sees Anne’s message and replies to both Jeff and Anne. Tim’s reply includes all of the previous messages in the Conversation. Conversation Clean Up can delete all of the messages except the last one from Tim because within that message is a copy of all of the previous messages.

To Remove redundant messages:

On the Home tab, click Clean Up.

Then choose one of the following:

o   Clean Up Conversation - The current Conversation is reviewed, and redundant messages are deleted.

o   Clean Up Folder - All Conversations in the selected folder are reviewed, and redundant messages are deleted.

o   Clean Up Folder & Subfolders - All Conversations in the selected folder and any folder that it contains are reviewed, and redundant messages are deleted.

Note: You can specify which messages are exempt from Clean Up and where messages are moved when they are deleted. 

For more Conversation Clean Up options see Outlook Help (F1 or Tell Me).