Change your email account password or mailbox quota
This article walks you through changing the email password for a cPanel email account or altering the mailbox quota (mailbox size limit).
Changing an email account password
Within the cPanel Email section, click Email Accounts - > Click Manage next to the email address you'd like to change
Then Enter a new password in the New Password field
Click Update email settings to complete the process.
Changing an email account quota
If a user is over quote, you can either have them remove email from their mailbox in their email client or webmail; or you can use the Email Disk Usage tool to prune older emails from the server.
1 - Within the cPanel Email section, click Email Accounts.
2 - Click Manage next to the email address you'd like to change
3 - Change the Storage Space quota or set to unlimited as required. Please note that disk space used by your mailbox counts towards your overall package disk limit.
4 - Click Update email settings to complete the process