If you wish to set Minimum Password Length for all the domains hosted under the server then you need to follow the below mentioned steps:

[1] Login into your Smarter Mail administrator account. Once you login, click on the Security tab.

[2] In the Security tab, under the Advanced Settings, click on the Password Requirements option.

[3] Now, provide password length in a numeric value and tick mark the Enabled check box.

[4] Now, click on Save button.

Note: We recommended to use bulk email verifier before starting an email campaign.