Easily block email by subject line in Outlook

Kutools for Outlook

Outlook is an essential tool for managing email, but users often find themselves overwhelmed by the constant influx of spam, which affects productivity and the overall experience of email management. Fortunately, with the powerful add-in Kutools for Outlook, users can solve this problem more easily and efficiently. The tool provides a straightforward way to block unwanted spam by subject, helping users better organize and manage their mailboxes, thereby improving the quality of work and life. In this article, we will take an in-depth look at how to use Kutools for Outlook to easily filter and block spam emails based on subject line, aiming to provide users with a hassle-free email experience.

One click to add subject of selected emails to the Block Subject rule
Manually create a rule containing the subjects you want to block
Easily manage blocked subject rules

One click to add subject of selected emails to the Block Subject rule

With the Block Subject feature of Kutools for Outlook, you can easily add the subject of multiple selected emails as a blocked email rule. When emails with the same subjects arrive again, they will be automatically moved to the Junk E-mail folder.

Hold down the Ctrl key and select the emails you want to add the subject to the blocked list. Go to select Kutools > Junk > Block Subject.
A Kutools for Outlook dialog box pops up telling you that a new email rule has been created. Click the OK button.
Tip: You can see the subject of the selected emails are listed in the dialog box. In this case, as I select three emails, there are three subjects listed in the dialog box.
If the Junk Email Filter feature is not enabled, the following dialog box will appear. You can:
- Click the Yes button: Clicking this button will enable the Junk Email Filter, and the emails you receive in the future will be automatically detected and blocked.
- Click the No button: Clicking this button will move only the currently selected emails to the Junk E-mail folder and end the operation.

Now you have created a rule named Block Subject.

Notes:

The relationship between the subjects in this Block Subject rule is "or", which means that incoming emails that match any of the subjects in the rule will be treated as spam.
If you select only one email and apply the Block Subject feature, the following Block Subject dialog box will pop up. The text box lists the subject of the selected email, which you can change as need, and then click OK to create this rule.
If you keep adding subjects of selected emails, the subjects will be added to the same rule named Block Subject in Kutools for Outlook. You can view and edit this rule by clicking Kutools > Junk > Manage Junk Email Filter.
You can also access the Block Subject feature by right clicking the selected emails in the mailing list and then select Junk (Kutools) > Block Subject.

Manually create a rule containing the subjects you want to block

The above method demonstrates how to quickly add the subject of selected emails to a Block Subject rule. If there is no matching subjects in existing emails and you still want to block emails with certain subjects, for example, you want to block all emails with a subject that contains the text "Super Low Discount". In this case, you can manually add this subject to a new Block Subject rule. Please do as follows.

Select Kutools > Junk > Manage Junk Email Filter to open the Junk management window.
In the Junk window, click the New button.
In the Create New Rule – Step 1 of 3 wizard, please do the following operations:
3.1) Select Block from the Rule type drop down list.

3.2) Tick the checkbox before subject in the condition list;

3.3) Then a Text Contains dialog box pops up, click the New button. See screenshot:
In the Search Text dialog box, you need to:
4.1) Enter the subject you need in the New Search Text textbox.

4.2) Click the Add button to add the new typing subject into the Search List.

4.3) Click OK to save the changes.
Then it returns to the Text Contains dialog box. You can see the newly added subject is listed in the Text box, click the OK button.
Tip: You can repeat the above steps to continue adding new subjects in this dialog box if you need. And the relationship between the subjects will be "or".
Now it returns to the Create New Rule – Step 1 of 3 dialog box. By default, the condition for this rule is "contain", you can change the condition by clicking the underlined text "contain", and in the popping up Create New Rule dialog box, choose the condition you need from the Subject drop-down list and then click OK > OK to save the changes. See screenshot:
Tip: To block emails with blank subject line, you need to select the 'is empty' option from the drop-down menu.
Finally it returns to the Junk window, you can see that the newly created rule named "Rule" is listed in the rule list, click the OK button to save the rule.
Tip: In the Rule description section, you can modify the rule such as change the rule name, change the rule condition and change the subject by clicking on the corresponding underlined text.

Easily manage blocked subject rules

After creating junk email rules using the above methods, you can easily manage these rules with the following steps.

Select Kutools > Junk > Manage Junk Email Filter to open the Junk management window.
In the Junk management window, you can edit the rule you created above.
2.1) In the rule list, select the rule named Block Subject or the rule you created manually.

2.2) Click the underlined text in the Rule description box.

2.3) In the opening Text Contains dialog box, you can add new subjects, edit a certain subject, remove a certain subject, or remove all subjects as you need.

Here are the steps for adding new subjects to the Block Subject rule.

1) Click the New button in the Text Contains dialog box.

2) In the Search Text dialog box, enter the subject you need in the New Search Text textbox.

3) Click the Add button to add the new typing subject into the Search List.

4) Click OK to save the changes.

Note: If you keep adding subjects in the Search Text dialog box before saving, the relationship between the new subjects will be "and", which means that the subject of the incoming email should contain all these subjects then can be considered spam.

2.4) Now it returns to the Text Contains dialog box. You can see the newly created subject is listed in the Text section. Click OK to save the changes.

Tip: If you want to temporarily disable a subject, just untick the checkbox before it.

2.5) Then it returns to the Junk window, you can see the Block Subject rule is updated. Click OK to save the changes.

Notes

To turn off the Junk Email Filter, go to select Kutools > Junk > Enable Junk Email Filter. Make sure that the tick symbol disappears before it.
To temporarily turn off a rule, go to select Kutools > Junk > Manage Junk Email Filter. In the Junk window, untick the checkbox before the rule and then click OK to save the changes.
The Example rules provided in the Junk window help to better understand the junk rules of this feature. You can delete them if you no longer need them.
A context menu is provided in the Junk window. You can right click on a rule and choose the option you need from the context menu.
Select all: Selecting this option will check all rules listed in the Junk window.

Unselect all: Selecting this option will uncheck all rules listed in the Junk window.

Inverse: Selecting this option will reverse the selection status of multiple rules within the rule list.

Select up: Selecting this option will check the currently selected rule and all rules above it.

Select down: Selecting this option will check the currently selected rule and all rules below it.
If there are multiple created rules in the Junk window, the rules will be executed in order from top to bottom.
In the Junk window, you can edit, copy, remove rules, clear, import or export all rules if you need.