Why does my Shopify mailing system only work for certain notifications?

[Abuksh]

Hello Team,

I have having issues with my mailing system from Shopify. When I cancel the order, the customer is notified. However, when I try to send the invoice via Shopify it displays an error message as "Invoice can't be sent from [business mail]. Verify this email address and try again".  Knowing that my mail works when I try to notify the customer about order being cancelled but not when I wish to send the invoice, I still when down to "Manage Account" but the mail shows a green tick and says verified. Having trouble why the mail is working only in some areas.