There are two types of filters in Trident:

Creating Email Filters

To create a custom email filter:

1. Click your profile image in the top-right corner of the app.
2. Select Settings from the drop-down menu.
3. Go to Mail > Filters.
4. Choose between the Incoming/Outgoing Email Filters tab. 
5. Click Create Filter.

Condition Type

These are rules that you can set to determine how the conditions you choose are processed. You can select one of the condition types below while creating a filter.

Any of the conditions (OR)

Emails will be processed through the filter when just one of the conditions is satisfied. For example: Set a reminder for all emails sent either to your email address or your team's group email address. 

All of the conditions (AND) 

Emails will be processed through the filter only when all of the conditions are satisfied. For example: Move emails to the "Respond Immediately" folder when they are from your manager and the priority is high. 

Advanced conditions (AND/OR) 

Advanced conditions use a combination of AND and OR condition types. Once you add the multiple conditions, you can switch between the AND and OR options by clicking them. 

To understand how this works, let's assume you create an advanced filter where the incoming emails can be from jacob.sanders@zylker.com or mary.hansley@zylker.com but must have the word "marketing" in the subject to be processed by this filter. 

With this advanced condition, the criteria pattern will look like this: (1 AND (2 OR 3)). According to this advanced condition, emails can satisfy either 2 or 3, but they have to satisfy 1 to be processed by this advanced filter.  

You can also determine the order in which the advanced conditions are processed by editing the criteria pattern from the Zoho Mail web app. This will be made available in Trident in future updates. 

Note: In an advanced condition type, AND will be given more weightage than OR.

No conditions. All incoming emails.

All of your incoming emails will be processed by this filter. 

Conditions

Filter conditions form the premise of what incoming or outgoing emails should be processed. You can choose multiple conditions from the following: 

Based on senders and recipients

Note: Delivered to and Bcc are exclusive to incoming email filters.

Based on email attachments

Note: Attachment Name and Attachment Type are exclusive to incoming email filters.

Based on email content

Note: Content is exclusive to incoming email filters.

Based on date

Note: Date is Between is exclusive to incoming filters.

Others

Actions

For emails that match the conditions, you can choose what email-centric actions should be performed from the following: 

Based on email management 

Note: Mark as Read, Set Reminder, and Snooze are exclusive to incoming email filters.

Based on deleting emails

Note: Delete and Delete After n Days are exclusive to incoming email filters.

Based on entity creation

Note: Add Email as Note and Add Email as Task are exclusive to incoming email filters.

Based on attachments

Based on recipients

Note: Auto Cc and Auto Bcc are exclusive to outgoing email filters.

Based on composing and sending emails

Note: Add Signature, Read Receipt, and Change Priority are exclusive to outgoing email filters. 

Unavailable Actions

The following actions will be available in future updates.

While you can't create or edit filters with the above-mentioned actions, you can view them if they've been used to create filters from the Zoho Mail web app. 

Skip Other Filters With Matching Conditions

To ensure that each email is only processed by one filter, check the Skip other filters with matching conditions option and place it at the top of your filter list. Without this option checked, if you have filters preceding it that match the same conditions, the email will be processed by all preceding filters before stopping at the one with this option enabled.

Actions such as Move to, Delete, Mark as Read, Flag as, and Forward Emails to will only occur once, even if the email meets the criteria of multiple filters with similar actions.

Filter Existing emails

To apply the newly created filter to previously received emails in a specific folder, simply check the Filter existing emails option. A popover will appear, allowing you to choose the desired folder. Once selected, the filter will be applied to those emails automatically.

Creating and Managing Filters for Multiple Email Accounts

When you have added secondary Zoho Mail accounts or have configured external email accounts (Gmail, Yahoo, Outlook, etc.) via POP/IMAP configuration, you can choose the email account for which you want to create filters. To do this:

1. Click the drop-down with the email address listed above the Create Filter button.
2. Choose the desired email account for which you want to create the filter.
3. Click Create Filter. 

Filters will appear according to the account selected from the drop-down menu. Actions and conditions accessible for your primary and secondary Zoho Mail accounts will also be accessible for external email accounts configured via POP/IMAP.

Editing Email Filters

To edit an email filter:

1. Click the filter you want to edit. 
2. Make the required changes.
3. Click Save. 

Duplicating Email Filters

To duplicate an email filter:

1. Hover over the filter you want to duplicate.
2. Click the Duplicate  icon. 
3. Make any required changes in the dialog that opens.
4. Click Duplicate.

Deleting Email Filters

To delete an email filter:

1. Hover over the filter you want to delete.
2. Click the Delete Filter  icon.
3. Click Delete in the confirmation alert.

Note: Deleting a filter will no longer process the incoming and outgoing emails that match the set conditions.

Applying a Filter to a Selected Folder

Once you've created an incoming filter, you can decide to run it for any folder of your choice later on. To do so:

1. Hover over the filter that you want to apply.  
2. Click the Apply Filter  icon.
3. Select the folder to which you want to apply the filter to, in the popover that appears.
4. Click Apply in the confirmation alert.

Resetting the Filtered Email Count

In the filters list, when you hover over a filter, you'll notice a number. It stands for the number of emails processed by that filter since the time it was created. You can set the filtered email count to zero and begin counting again from the reset date by clicking the Reset  icon next to it.

Listing Filters in the Right Sequence

Your incoming and outgoing emails will be processed through all of the created filters with matching conditions in the sequence of their listing. So, it's important that you order your filters accordingly. 

While it's not possible to change the sequence in Trident (will be available in future updates), you can do so from Zoho Mail web settings. 

Searching for Filters

To search for filters you've created:

1. Click the Search  icon next to the Create Filter button.
2. Type the keyword in the search box, and all matching results for filter names will be displayed.