I suggest making sure that your Send Forms Preferences has the correct settings for your email. You may also need to set it up again to make sure that it will work properly.

Here’s the link that will guide you on how to set up your email in QB. 

Resolution for 'Forms Preferences issue: 'email password will not work' available: Yes.

The Forms Preferences issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the Forms Preferences issue yourself by looking for a resolution described in the article. If it is a complex Forms Preferences issue or you are unable to solve the issue, you may contact us by clicking here or by using other Forms Preferences support options.

For more information about resolving issues related to Forms Preferences in Quickbooks/QBO or to get support for the issue 'email password will not work', click the link below: