Emails are sending with the incorrect 'from' email address

If you notice that the 'from' address configured on an email notification is not the address used when sending the email, it may be due to formatting or a third party filter modifying all emails sent. 

Check to make sure the value you entered in the from setting is either a valid email address or in the format:
Name <EMAIL_ADDRESS>

If the email address formatting is correct, it's more than likely a third-party plugin hooking into WordPress' wp_mail() function and modifying the headers. Try disabling plugins that augment WordPress' email system in some way to see if you can find the plugin interfering. Once the problem is isolated, either disable the feature in that plugin causing the issue or reach out to their support to see what other solutions might be possible.