To increase the email size limit in the DirectAdmin web control panel, you can follow these steps:

Step 1: Login to your DirectAdmin web control panel

Step 2: Navigate to E-mail Manager > E-mail Accounts

Step 3: On the row with your email, click the + sign and select Change Limits entry

Step 4: Enter the new quota value (in MB) and click the SAVE button.

By following these steps, you will have increased the email size limit in the DirectAdmin web control panel either for a specific email account or globally for all accounts. Keep in mind that there may be other factors such as server configurations or email client settings that could affect the actual size limit for sending and receiving emails.