There are a number of ways to do this depending on your email provider and email client. Generally speaking, you can use rules or filters to do things such as delete all emails received prior to a certain date, with certain subject lines, or containing certain words in the subject line. You can also set up retention policies on particular folders to automatically delete or archive emails older than a date you specify. Additionally, you can also set up tags or labels to automatically apply to email based on rules or filters, organize with folders, and use some combination of tags/labels and rules/filters to automatically move email into folders based on preferred conditions to help keep your inbox organized and delete.
We recommend Mozilla Thunderbird as an email client. You can use Thunderbird to set retention policies to take action, such as move or delete email when it’s older than a certain age or date. You can do this on your inbox and other folders you create, in addition to using filters and rules to move or delete email.
Retention Policies in Thunderbird:
To set a Retention Policy on a folder, click on the folder on the left, right-click and select Properties, and click the Retention Policy tab:
Filters in Thunderbird:
The location for configuring filters can be found by clicking the Settings button (three horizontal bars in the top right) and Tools:
From here, click Message Filters:
Create new filters by clicking the New button on the right:
And create filters using the menu. You can create filters to do a great deal of things, such as move certain emails to folders or delete them. In this example, this filter, which is named “Newsletters to Junk” will be manually run and will set the status of all emails with a subject line containing “Newsletter” to Junk: