Answer
You Control Your Outgoing Emails
If emails sent from Lightning Payroll are being rejected or marked as spam, it is beyond our control.
Lightning Payroll (Desktop version) sends emails from your mail server, not Lightning Payroll's. You can configure this under Company >> Email >> SMTP Server Settings.
Lightning Payroll (Online version) sends emails from our mail server. These emails will always come from our support@lightningpayroll.com.au address. The same applies when you use the Have Lightning Payroll send emails for you, instead of using your own email provider? setting in the desktop version.
Avoid Google Spam Filtering With Best Practices
Gmail/Google in particular have very strict anti spam and anti spoofing practices (that can change at any time) which can result in rejection of emails if your mail server is not correctly configured. SPF, DKIM, DMARC DNS records are the most important factors in mail filtering. If Lightning Payroll gets a 'success' response when sending, from your outgoing mail server then the email has been sent. What happens after this is completely outside of the control of our software.
For more information please see here to learn more about Google's best practices to avoid email rejection. Advising employees to check their spam/junk mail and unmark your emails as spam can also help train receiving mail servers for better future filtering.